topic Re: Re: Re: S26 Ultra randomly restarting in Galaxy S26

S26 Ultra randomly restarting

jdmackes1 — Mon, 23 Mar 2026 19:42:48 GMT

I've noticed with my S26 ultra that it will randomly reset sometimes and I wanted to see if anyone else either had this issue or knew of a fix for it. I used smart switch to transfer the data from my S25 Ultra to this phone using the USB cable just for reference. I wasn't sure if it was randomly resetting until just now when it reset while I was in the middle of watching a movie on Plex. I had the phone on my wireless charger, so it was sitting around the 80% charged limit that I set for it. I've noticed it will do it randomly other times even when I'm not using it (like it appears that it restarted in the middle of the night last night, and I'm pretty sure I saw it do it once before when I just had it sitting in front of me).

Are there any tests I can run or logs I can inspect to see what is going on, or do I just have a defective phone?

Re: S26 Ultra randomly restarting

Mujibar — Mon, 23 Mar 2026 20:14:03 GMT

My S26U behaves normally and isn't experiencing anything like that. If you transferred apps from your old phone in addition to data, the random reboots could be due to something that came over in the process. A factory reset will probably set things right.

You can run a diagnostic if you want. It can be found under settings > device care, or go to the Support tab in the Members app and tap "get started."

Re: S26 Ultra randomly restarting

JR2277 — Mon, 23 Mar 2026 20:07:04 GMT

Maybe you have it set to restart when it's experiencing a slow performance. Check in your settings for Performance and check all the settings there and run tests in that section also. If it doesn't find problems and it still does the random restarts I would try to exchange it.

Re: Re: S26 Ultra randomly restarting

Mujibar — Mon, 23 Mar 2026 20:55:04 GMT

Good thought! I hadn't considered it being caused by an actual setting.

Re: S26 Ultra randomly restarting

AAbbott — Mon, 23 Mar 2026 21:00:04 GMT

Settings, device care, auto optimization - check the settings to make sure you don't have it set to restart when necessary. It is supposed to warn you, though.

Re: S26 Ultra randomly restarting

jdmackes1 — Mon, 23 Mar 2026 22:03:53 GMT

It is set to restart when necessary, but I was only running plex and was actively using my phone when it reset. There was no warning, no slowdown or issues and my phone had last restarted earlier in the day (overnight when I wasn't using it).

Re: S26 Ultra randomly restarting

AAbbott — Mon, 23 Mar 2026 22:46:30 GMT

Then it's some other bug that's causing it. Might be a third party app. Try optimization using Good Guardians' app booster. Also, turn off restart when necessary and instead restart on schedule. It's not supposed to restart while you are actively using the phone.

It will restart if your phone is overheating. Your phone does not have to feel hot to be overheating, but the internal sensor will detect the condition. However, it's been my experience that there is always a warning when the phone is overheating, and it will first slow down and only restart if the overheating doesn't stop.

Re: Re: S26 Ultra randomly restarting

jdmackes1 — Mon, 23 Mar 2026 22:56:10 GMT

I sent in the report about the phone freezing and restarting to Samsung, I wish I could access what it said but all I could see was just the time stamp information. Thanks for the responses, I'll give them a try!

Re: Re: Re: S26 Ultra randomly restarting

JR2277 — Tue, 24 Mar 2026 02:30:47 GMT

If it's setting then something is causing it to trigger. The device might be overwhelmed by lots of apps or a couple draining ones 😂

Re: S26 Ultra randomly restarting

JR50 — Tue, 24 Mar 2026 04:39:39 GMT

Check optimization feature to see if auto restart schedule is active. If you transfered from another phone, if so delete restart schedule

Re: S26 Ultra randomly restarting

userCYfiehAGdw — Wed, 25 Mar 2026 01:26:21 GMT

Same issue multiple times daily. I've spent 3 hours on the phone with tech support and hard reset twice. When not using smart switch it ran fine (stock apps only and YouTube ran) for 3 days, but, Evidently some app from my s25u (hundreds of them) isn't compatible with either the new UI or the new Android. So far I am eliminating one by one apps that are showing up in the battery usage list First. It does not appear to be nova launcher, smart launcher 6 or assistive touch. Is run 3 hours with gravity screen disabled, so I'm Hoping it's that one. They have me One extra week for the trade-in return but again, ran fine with stock only apps; probably good with Galaxy store apps too

Re: S26 Ultra randomly restarting

userCYfiehAGdw — Wed, 25 Mar 2026 01:28:14 GMT

Same, see my detailed reply above

Re: Re: S26 Ultra randomly restarting

jdmackes1 — Wed, 25 Mar 2026 01:51:07 GMT

Interesting. Mine did it again today while I was listening to music, just quickly shut down and restarted. Only took a couple seconds, but it's very odd. I've also been removing random apps that I either don't use or have some concern about. None of them have been using a large percentage of my battery though or even really running much. Not sure what the issue is.

Re: Re: S26 Ultra randomly restarting

SamsungMod — Wed, 25 Mar 2026 14:05:23 GMT

Thanks for reaching out, @userpersonguy! Along with the tips everyone else shared, here’s a Samsung troubleshooting link that might help too:

http://www.samsung.com/us/support/troubleshoot/TSG10001531/

Give it a shot and let us know if it helps!

Re: Re: Re: S26 Ultra randomly restarting

jdmackes1 — Wed, 25 Mar 2026 14:27:59 GMT

Nope, none of those would help. The battery wasn't low (it was on my wireless charger and at 79-80% which is what my battery setting is). No apps were using a high amount of power at any time it has restarted. Nothing was around the phone, it was just sitting. Its also happened since I've forced a restart on the phone and after I've run app optimization and everything else suggested in this thread.

I've got to think it's from some random app that doesn't work well or something so I removed some random apps that I don't use anymore and I'll see if that fixes anything.

Re: S26 Ultra randomly restarting

jdmackes1 — Thu, 26 Mar 2026 15:21:39 GMT

So I've done everything that everyone has suggested. Diagnostics all passed with no issues. Good guardians app booster was run and optimized everything. I've deleted random apps. My phone states that it has never restarted due to auto optimization. My phone is not overheating or dying cause of a low battery, or having buttons pressed and causing it to shut down, it is simply doing it on its own.

It happened to me last night at 2:30 am (my dog woke me up and had to go out) while I was in the middle of listening to some music. It happened just now as I wasn't even doing anything on the phone (I had been watching a video, but it was paused and I believe the screen was off as it had timed out). I don't particularly want to have to reinstall everything to test if it is an app. I'm also a little wary about this issue seeing as how my S23 ultra just randomly decided to die after a year and a half of use. I'm leaning towards having the unit replaced unless there are any known ways to really see what is causing the issue.

Re: S26 Ultra randomly restarting

SamsungMod — Thu, 26 Mar 2026 15:38:44 GMT

Thank you for reaching out @jdmackes1. As you have tried all the troubleshooting steps, the next step I would recommend is submitting an error report. The error report will allow our team of engineers to get a hands-on look at the logs for the symptoms you are experiencing. Give this link a try for the steps to submit an error report: https://us.community.samsung.com/t5/Samsung-Care-Tips/How-To-Submitting-Error-Report-Feedback/ba-p/3001692

Re: Re: S26 Ultra randomly restarting

jdmackes1 — Thu, 26 Mar 2026 15:49:17 GMT

Thanks for this. I've submitted a few error reports already (when the notification would pop up) but I had not submitted feedback with the error log before. I've done that now so hopefully there will be some answer on what is causing it. Thanks!

Re: S26 Ultra randomly restarting

jdmackes1 — Fri, 27 Mar 2026 13:03:42 GMT

I'm thinking more and more that my phone is just defective. It's seemingly getting worse as it's now restarted at least 5 times in the last 24 hours. I tried to use it yesterday to text and the screen was completely frozen; after a second or two it flashed up a static screen (very similar to how my S23 ultra looked when it would die out) and then shut down. I had to hold down the power button to get it to restart.

Re: S26 Ultra randomly restarting

Members_f2HhKT9 — Fri, 27 Mar 2026 13:36:11 GMT

My S26 Ultra is experiencing random shutdown and reboots, as of Mar 26, finally became very hot to the touch, shutdown, rebooted, then went into some software update, the shutdown, then even more thermally hot. At that point, the phone is unable to be restarted. I have a case in effect with Samsung and a claim. The phone is dead, unable to force restart, unable to charge, you get the idea.