I have a Galaxy 2019 Tab A it is described as.

I unlocked it this morning using my four digit passcode and checked for updates as usual.
Then checked my McAfee virus protection for updates.

Looked at the news and after 10 minutes or so allowed the tablet to sleep.

4 Hours later I tried to restart the apparatus.

It seemed to accept my four digit passcode but then gave a message "try again in 30 seconds."

It will now not allow me to turn off, restart, or do anything until I log in using using the 4 figure passcode which always displays "try again in 30 seconds."

I was using my laptop when I received a call on Skype which also came through on the tablet but I was still unable to get the tablet to accept the passcode.

I am totally lost with this one.

Any assistance would be appreciated.

Thank you.
Dave