That big hammer is very handy. We have a large wooden mallet in the office with "Attitude adjuster" on it. Unfortunately, waving it near a PC doesn't seem to help
I'm glad you solved it. It did occur to me later that the database might have been corrupted. That can also explain these symptoms. If you see something like this again, try logging out of the account on the device
first. This will create a new database when the device is restarted. It's a smaller hammer.