hand control Nexstar issue

hello,
I have a Celestron nexstar. At night the bottom scrolling screen is all gibberish text. It seems to be typing over itself as it scrolls.
First I tried to update the controller. completed no issue and now has latest firmware. Second, adjusted brightness. Third, adjusted scrolling speed.
No positive effects on problem. Any experienced members with some potential insight?
Thanks

Brian was it very cold out, if so wrap a dew heater strip around the HC or one of the chemical heater like the hand warmer, the display tends to get very sluggish when it's cold.
HTH Pete