I have a feeling this is related to the body control module. If you look at the attached pics, I included the entire wiring schematic for the instrument cluster. In the first pic, I highlighted the panel lamp driver at the BCM. That wire goes to the instrument panel. It is an orange wire.
What I need you to do is check if there is power at the wire when the lamps fail. It would be nice if you could get a test light on it, turn the headlamps on, and then see if the test lamp slowly turns off. If it does, then I would suggest checking the connection at the BCM to make sure it isn't a loose connection or corrosion causing a power loss.
If the test light does the same as the cluster lights and there are no problems at the BCM connector, chances are the BCM is bad.
Here is a link you may find helpful when testing the wiring:
Let me know what you find or if you have other questions.
See pics below.
Images (Click to make bigger)
Tuesday, April 13th, 2021 AT 8:29 PM