When this happens, are there any other lights affected or is it only the HVAC control display?
I attached a picture below (pic 1) that shows all interior panels illumination. The second pic shows relays related to the unit. I have never experienced this type of issue, but lets give it a try. First, locate the relays related to the HVAC. Next, since you hear a clicking, it does sound like a relay, so see if you can feel the click from one of the relays indicated.
Let me know what you find.
Images (Click to enlarge)
Friday, April 30th, 2021 AT 4:36 PM