I noticed that my shell isn’t completely flat

Probably a good idea to quickly pop it open and have a look at the battery. Opening the steam deck is quite easy (remember to remove the SD card!), It only takes 3 minutes to check :)

I’ve reached out to Steam Support atleast, hopefully they can directly sell me one, or point me somewhere that I’m not buying one off Amazon

From what I understand, iFixit is their official partner, valves support website directed me towards that as well.

When did you get your steam deck? Mines an original Q3 an curious if this is something common for our 2 year old devices?

August 2022, close to three years old now.