Battery Connections/Fuses: First thing I'd do ...and this is quick and cheap: check your truck battery connections, grounds, batt>body grounds, etc? Also wiggle and re-set the fuses and the fuses/connections at the pos battery connector.
Major Grounds: Look under the plastic cover by the front tire for the major ground there. Mine is super rusty on my truck. And there's a major ground back by the gas tank filler neck on my truck. These all can get real rusty if ya live in the rust belt.
IP Cluster: Next step is to remove and re-install the instrument cluster connector to ensure there's a good connection there as well. That might be the root of the problem. Most electrical problems are caused by flaking connections and bad solder joints, not failed components. So start with the major connections/ground first (batt/fuses/grounds/etc) and work back to the IP panel. Flaky electrical connections cause poor voltage and chips and electronics act 'funny' when they don't see the voltage they need. If you're DIY and all the above hasn't worked, crack the instrument cluster open and inspect solder joints with a strong magnifying glass or jeweler's loop. Re-solder the main connector and LCD solder points. There's probably a youtube video on these LCD's.
90% it's one of the above.
[Edit] One thing I didn't mention are in-cab grounds. A lot of time they become rusty from cab leaks, etc. Grounds are so important there are several on vehicles nowadays. The IP cluster probably pulls from a nearby ground on the dash support somewhere. But if it pulls from the floor and there's a rusty ground there, that could cause problems too.
