I had a similar issue after the LT handle install, the door lock would not go all the way up if someone tried to open the door while I pressed unlock.
A few tries of lock/unlock the door would open.
For me the issue ended up being the plastic clip had come out of the door panel, the one about 3/4 up in the middle of the door (since I stressed it a little getting it out). I re-installed it and the door has operated fine since (about 9 months). I didn't think that would actually cause the issue and was surprised that it corrected it.
Not sure if that is your issue but I would check that cable, it seems to be pretty sensitive to it's location, etc.