You probably have a bad connection feeding into your dome light (if it's not just the bulb itself). If it was a fuse, all of the dome lights (and a few other things) would not work at all. Google instructions on removing your dome light and check the plug in behind it. Getting all of the dust out of there and reinserting the plug may fix the issue.
I removed the dome light on my 2016 Gen 3 3 and it wasn't very difficult to do. A couple screws and some wiggling got it down.
Hmmm... I would put it back together. It's probably a loose wire or connection somewhere internally... since it turns on when pressing the button, but doesn't stay lit after releasing it. You may need to buy a new dome light and swap it out...