Hey @Starchaser ,
The lifting is due to the battery expanding. While the phone may be operable I do not recommend that you continue to use it as it may potentially cause more damage to the device and yourself. The battery may be replaced at your local ubreakifix or Samsung Experience Store though they may be closed, contacting the 800-Samsung number is also an option. If this was helpful please give a like and check off the solved icon.
Ddsanchez_82, thanks for the reply. I am aware of the reason the phone is expanding, but a battery in a 2 year old 1200 dollar phone should not be doing this. It is the result of a poorly made battery, therefore a hardware issue which should be taken care of by Samsung.
While I understand the frustration there are too many variables on why and how this may have happend. Things like charging habits and what was used to charge the device would be varified during the Samsung daignostic process. The device is also outside the manufacturer warranty and is most likely not going to be covered. Though the device is out of warranty I can confirm that the cost of a battery replacment is only $59 as long as it is only the battery. I know that it may not be the response that you want to hear but I really hope that it was helpful. If it was please marked as solved.
It has more to do with what youve been putting in it. If you keep feeding it junk food, its gonna get a belly. Just like people. We expand around the middle with time too. Lol!
I'd recommend to stop using fast wireless charging and fast wired charging. On my note9 there is an option to turn fast charging off.. as batteries get older the do get baterry degradation, an it happens much faster from charging your phone overnight and from using your phone while its charging. I'd recommend getting the battery replaced or buying a nice used or reconditioned unlocked note9, the note9 also has android 10 one UI2.0 and will be getting one UI2.1 when it launches.. plus the note9 can be picked up for around $300 now, I'll be using my note9 for another year at least, it's a very capable phone still today, no lagging and battery still last a full day easily