In Maya the face selection for my character's body mesh is all bonkers-crazballz (see image), but face selection for other meshes in the scene behave normally. I tested the mesh in Blender and it selects fine there, so it seems like it's only broken in Maya. The model is an FBX imported from zbrush.
I had already made sure there were no selection constraints and I had reset the selection tool, as well as froze transforms and reset the pivot. Also deleted history, but it's still bust );
Open up the tool settings (you can just double-click the select tool) and hit "reset tool". See if that does anything. Might wanna reset the pivot of the whole object, and freeze transforms. Just to be safe.