Found your thread because I was having a similar problem. Built an outpost where a couple Hitchhiker modules would pivot out from the main structure. 1 hinge just wouldn't budge. First I was using a KAL to control the motion. Then I deleted the KAL and tried with custom action groups. Unfortunately I couldn't find anything to correct the issue. Ultimately had to disassemble those units and recreate them. After that, they worked fine. Still no idea what caused the issue