Hi Bob,
Have you tried a hard restart on your tablet?
Start by holding down the Power key for a short while in order to turn off the device.
After that, press and hold simultaneously the Volume Up & Home & Power button for a few momements.
You should release held keys as soon as the Samsung Logo appears on the screen.
When the tablet fully starts up again, see if this has fixed the problem.
Rupert
March 2020