The cable conataining this channel is OCT1 e- C.
Yester day I replaced the connector on the decoder end of the ribbon cable, which did not change the situation (I believe I made a log book entry). Today I exchanged the complete cable during run 31077 and that seems to have fixed the problem.
I replaced the remaining connector on the original cable and swapped back to the "repaired" original cable before run 31079. ---> cable still bad. Stopped run after a few minutes, and replaced the bad cable with the previous temporary cable before run 31080.