Laptop stuck in tablet mode, sensor problem? (kb and touchpad off)

My laptop worked in both modes with windows and linux for some years now, but in the last months I noticed some funky behavior with the switching of the modes: while the switch would typically occur after folding the screen at a full 360° (on Fedora), it started doing it at 90°, sometimes getting stuck for a bit or until i fully closed and reopened it.
That wasn't a problem, but now it's just stuck in tablet mode, with deactivated keyboard and touchpad, like the sensor suddenly vanished. The worst part is that this seems to be governed by some low level system, because even in the bios the keyboard doesn't work.

Has anyone heard of this problem or has any idea of where the sensor is located? It's like the third major problem that this specific computer had in it's lifetime, and it's getting kinda frustrating.
Thank you!