A perfect point with the endpoint number. This is definitely a clue.
I have factory reset twice the problematic device, as suggested. It didn’t help.
Then I tried to remove and add a device that worked in a guest bedroom and after re-inclusion, it ended up using endpoint 0.
guest bedroom.log (5.0 KB)
The wiring of the dimmers is the same.
Someone else had this problem as well here. But the debugging wasn’t properly finished and ended up with another problem that dimmer and button were added securely and non-securely (all my dimmers are added as non-secure).
@chris wanted to see the inclusion log and node XML, attaching it below, the NODE 23 was added. The log file has 4 MB, uploaded to dropbox: inclusion-node23.log.
network_c9148173__node_23.xml (44.7 KB)