2017 GMC 2500 hd electrial/computer issues

[prkeeleyiv]

Hey guys hopefully someone can help me out with this.  I have a  2017 gmc 2500hd lt that ive owned since new with 45,000 miles.  Trucks been great until recently when i started having electrical/computer issues.  The DIC would start displaying crazy messages like put drivers side window up and down, trailer brake enabled when no trailer was attached, stabilitrak and so on.   Would also hear a weird audio noise when in the truck driving sometimes.  Anyway the one day after truck was acting crazy on the ride home from work i stopped for coffee and turned it off and the truck went completely dead.  Not a light, key fob woudlnt work, door locks, nothing.  Dead like a light had been left on for the entire last 2 days.  So i got a jump and truck started right up and  i had the battery tested that day and it checked out 100 percent perfect.  Took to dealer and they couldnt find any issues but must have reprogrammed something because truck was fine for 6 months and now it left me with a dead truck again the other day.  At the dealer right now again and they cant seem to find anything.  Truck doesnt have any crazy mods besides  a rigid industries set of back up lights since new and led bulbs in the oem tailights.  Those mods were done when almost new and didint affect anything and arent wired half assed so i kind of ruled them out.  Was looking online and saw maybe the negative battery cable or some of the grounds like g218 and g210??? Really sucks because i enjoy the truck but having a truck which just goes dead for what i paid is unacceptable.  Thanks