Welcome to the PSR Tutorial Forum, Twice!
I don't think this is a software problem (which could be fixed by restoring a backup), but it might be a hardware problem. An internal cable connector may be loose or may have poor electrical contact. I'll look in the T5 Service Manual to see which internal connectors/cables it could be and then I'll get back to you here.
P.S.
In some cases you can use the data entry dial and the Enter button instead of using the A - J display buttons.
Best regards,
Chris