Are you using the original charger that came with the device?
-If no, I would recommend using an original Samsung Charger.
Do you experience these symptoms if you try to charge your device in safe mode? If your phone is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe Mode feature. In Safe Mode, your phone won't run any third-party apps. This allows you to easily identity and remove the app that may be causing the problem.
I would also recommend checking your charging port to make sure there isn't anything blocking the charging connections. Lastly, you can try a factory reset, which will give the device a clean, fresh start. Be sure to back up everything you wish not to lose beforehand: https://www.samsung.com/us/support/answer/ANS00062029/
If the troubleshooting is not helpful, the phone will need to be evaluated by a certified technician.
You can use the following link to find a list of service centers in the U.S. that can do the repair:http://www.samsung.com/us/support/service/location or by contacting customer support at 1-800-726-7864.
Samsung offers a variety of repair locations, including walk-in Samsung service centers. Select the product that needs service to find a location near you.
I am having the same issue on my Samsung Galaxy S10 plus... this is the second time it's happened... I think I just blew in the port the last time and it started working... but I also remember my fast charging not being set... but I checked and it set this time... So I'm looking for an answer as well.
Invariably, I find with my phones that it is the rather mundane problem where there is a build up of 'pocket lint' in the port. This stops the charger making a good connection. I find a strong light, magnifying glass, and a thin pin allows me to clear out a shicking amount of dust and detritus. It can be quite embedded so tapping your phone on something hard is unlikely to dislodge it - you need to drag it out with the sharp end of your pin. Or you could just get a new phone like 90% of people probably do!
Safe mode did nothing for my phone, and I had blown in the port, used contact cleaner etc, all with no results. I couldn't really see with the magnifying glass, but I tried your idea with the pin and that did it!. Started to bring up some lint and thought I'd done it. Then I started scratching lightly with the pin on one side and noticed I wasn't getting the telltale feel/sound of metal on metal (or plastic) so I scraped a bit harder.
The lint really started coming up then, in ridiculous amounts. It was impacted right at the back which would have been hard to see with the magnifying glass anyway. I had probably made it worse with the contact cleaner and repeatedly forcing the cable in there out of frustration!
Now works perfectly!
Remember that you do have a charging port and you could damage some of the contacts, so don't go crazy - but I definitely think before you take the phone for repair, you should give it a good go with a pin first.
