Try resetting the tools and/or preferences. To restore preferences quickly using a keyboard shortcut:
Press and hold Alt+Control+Shift (Windows) or Option+Command+Shift (Mac OS) as you start Photoshop. You are prompted to delete the current settings. The new preferences files are created the next time you start Photoshop. Note: Using the keyboard shortcut, preference files for custom shortcuts, workspaces, and color settings will also be reset to default.
Tried it out. It was working fine, but then just froze again. No error appears or a crash. It just freezes on the image and becomes unresponsive. I then have to do my best to save the image and then reopen it. It is a very big pain.