I've been having this issue were in blender edit mode would randomly stop working. I couldn't select anything (verts, edges, or faces) unless I went into wireframe mode. Edit mode simply wouldn't allow you to select anything while in solid mode.
After throwing a tantrum and asking "why" about 100+ times, I think I finally figured out something.
So if you're running Blender and OBS (streaming software) at the same time errors start to crop up just like this one. I tried restarting Blender, my computer, and OBS, but the result is still that same. As long as I'm streaming with OBS blender's edit mode stops working correctly.
Are there any fixes for this?