Gremlins?

[Hart_graham]

2015 transit custom 2.2 camper conversion.
I know this topic has been on here before but......
Every now and again after driving the van I go to lock it with the remote and....it locks, horn beeps and it unlocks. I open and close the door again and lock it again and it does the same. I go right round the van and open and close all the doors (5) and it still does it. I tried cleaning the sliding door contacts but it makes no difference. Then I try again maybe an hour later and it will work ok. But not today. Today I got in the van and locked it with the drivers door switch and then unlocked it again, got out and locked it with the remote - no beep, all fine. I've tried unlocking it before I lock it but it makes no difference. DOIN MY HEAD IN!
Help

[Hart_graham]

Found the 'gremlin'. Drivers door loom had broken wire where it passes through the flex section between the door and pillar. Discovered that this is a real prob with transits and appears in quite late models such as 2017. Have repaired loom for now whilst awaiting new loom.