I’m really not sure what happened but at one point, my armature got duplicated without actually existing.
I can only access it in the menu pictured above and it replaces the other armature when selected. This happens vice versa. My main issue currently is that one armature has the keyframes for animations and the other has the animations despite not having any keyframes. I tried duplicating the whole thing but when I go to another tab to do it one of the armatures vanish. The one and only way for me to access this phantom armature is by reloading a specific auto save. I pressed the shield icon on both of them but to no avail. If I save and load any other save the phantom armature, once again, vanishes.
The actual issue is that this way Blender can’t export it.
I’m in a kind of lucky position that if I have to redo my work it’s “only” about 2 hours of work but I’d rather not if possible.
Edit: managed to backup the save and it opens it exactly as it has to. Can’t post it here 'cuz I just registered but got it on drive if anyone has any interest in solving a mystery: https://drive.google.com/file/d/1x7kppWf1WArRCy2x4pT5S4sJJR4wKX6t/view?usp=sharing