I have an older tom tom unit.

Had a similar problem.

There is a reset button (you have to access it with a paper clip) on the back of my unit. Has happened a couple of times in the last 3 years. I or my wife use it daily. Always fixed the problem.

Also, I had a unit fall off the dash when the suction cup ripped from
constantly changing cars. Screen crcked.
It was within 1 year of purchse. Tom Tom sent me a new unit.