Thank you all for your help and ideas!
@jeremyrumpf
On a quick look I did not find a similar log entry. Maybe I have to wait, until the binding “hangs” again.
Pigpiod and openHAB are running on the same machine.
Between pulses there are at least 10 sec, so that should not be a problem.
I have seen (via some googling) that you have published a new version of the binding ([GPIO] New GPIO Binding for OH3 - #81 by jeremyrumpf). Shall I try this version?