Trip computer fades when vehicle key is out of ignition

[VUCOM02]

I've recently had a problem where my trip computer has stopped displaying when key is out of ignition the total kilometres fades away and also the cars beeping noise has stopped working any ideas how to fix.

I've recently had to remove the battery to install a 21 inch led light bar and also foglights but my battery is still holding 12.3 volts when off and 13-14volts when engine is on. Would anybody know why this has occurred. Cheers.