Apple Watch 4 Screen detached

I have a 44m stainless steel apple watch 4. The screen detached (possibly while charging), but other than that everything seems to work including the force touch sensor. I brought it in to apple genius bar and they suggested that I have it sent in to repair depot. I was told that if the detached screen was caused by a swollen battery, the repair would be free. The repair depot found that the battery was not swollen and wanted $519 + tax (CAD) for repair. I had the watch returned without repair.

Based off of the above photos I am wondering if apple might have been wrong about the swollen battery. If the battery is not swollen, I am wondering what the best way is to repair it?

I already ordered ifixit apple watch series 4/44m adhesive, but after some more reading I am not sure if that is what I need. The screen is still attached to the force touch gasket except for the corner near the home button. Do I need a new force touch gasket? If not, is there supposed to be adhesive between the gasket and the main part of the watch or does it just sit there? If I need adhesive for the gasket, what do I use?