It is a bug in the modem, for some reason if you let the wifi on , with the data on, the batery drain , just disable the wifi when leave your house and you will see a big difference in the batery endurance.
Samsung doing this kind of bug to make to you to change to a new models like a S10.
This will be my last samsung , im wasnt to believe this, but is thruth they never doing the updates well, because if the device work well no nobody prooceed to buy a new model.
If it is truly a bug, which I don't believe it is, why would Samsung not immediately push out a patch? Bug fix? Address the issue before it gets worse and maybe the media or an influencer pick it up?
As I wrote above,it is just Samsungs heavy skin using a lot of power after the Android pie update. This is why they put much bigger batteries in their new flagships. I'm sure as Samsung improves the software going forward, and keeps putting bigger batteries in, the battery life will get better.
But for all of us that are stuck with a 3500mah battery in our 2018 'flagship' phones we are SOL.
So it just proves how much Samsung gives a dang about their customers.
I was on Android 9.0 Samsung one UI Beta 4. I had really great battery usage. I recovered a small 238 mb update for the official release and now It's using 15 to 20% when in stanby and idle. I found a temp workaround that gave me great battery usage for a few days. It's a bug no doubt.
I would recommend taking this up with your service provider. You could have a faulty sim card or your phone settings could have accidentally been changed.
Once again this may not necessarily be a phone issue. This post is regarding battery drain issues so I recommend making a post regarding your service issue seperately. But please check with your service provider first and keep us updated as to what the issue was.
Best of luck.
I have to say that this flagship S9+ was supposed to be having 3800+ mAh battery. Some people are irritated about this issue and mods are replying which shows no care at all, they say turn off wifi, bluetooth, nfc, location, aod, edge lighting, mobile data, torch, auto rotate etc then why Samsung putted this sh*ts into their mobile.
I just shifted from Note 8 and purchased S9+ so I got a direct update to 'Pie' thats why I am not feeling any BAD battery consumption.
My S9+ gives me 6 Hours in all cases when I use heavily possible (from 100% to 16%). However, When I don't use whole day and on 25-35% brightness then it gives me 8-9 Hours.
Samsung, also please stop providing unnecessary apps by Smausng Electronics. Also please on next update provide us the best possible battery consumption because 6 Hours in actual is nothing.
7-8 Hours are enough when you use at 35% brightness and I personally say S9+ is providing the great battery lifetime and keep it up in next update.