360 Spider Gear indication

After sitting for several months i started our 2005 360 and noted that when reverse was selected the R was flashing and the gear selection would randomly go back to neutral

I think that when 1st was selected the 1 in the display was also flashing.
i also note that orange check engine light on the left side of the cluster was also illuminated.

I turned off the battery and left it for 5 minutes and tried again and found the problem still present. After persisting for a few minutes the flashing indications stopped and all is now well.

Can someone please tell me what may have been the problem.

Thanks for your assistance in advance.

Kipper