First post here, but I have some experience with replacing the low beams and fogs on my 2015 Longhorn CC (factory projector housing).
Ordered mine from xenondepot.com. Went with LED replacements for the low beams (9012) and fogs (9006). Low beams had an option for CANbus adapters that I paid extra for, fogs did not.
Installed everything and the driver side low beam would stay on for about 30 minutes and then go out. It'd come back on intermittently. Also, the driver side fog would almost immediately flash about 3-4 times and then go out. It'd come back on when the truck was turned off and back on again. Contacted Xenon Depot who promptly answered that resistors would solve the problem and sent them to me that same day.
Resistors are still on their way, but I had some time to play around with everything yesterday afternoon. I removed the CANbus adapter from the driver side low beam and put it on the driver side fog - fixed the problem. It stays lit. So, that caused the driver side low beam to behave exactly the same as the fog had - would flash and then go out. So, I took the CANbus adapter off of the passenger side low beam and put it on the driver side low beam - voila! It all worked.
So, I can't explain how or why, but with the 9012 LEDs in the low beams and 9006 LEDs in the fogs, they work with CANbus adapters installed ONLY on the driver side lights. Weird. No bulb out messages in the EVIC, flickering, flashing. Took the truck out for almost 1.5 hours last night without any issues.