Zigbee Devices Not Responding After C5 to C8 Migration

[Tony]

Have you tried the latest update (.125)? Your problem sounds very much like the one discussed in this thread which that update apparently has solved:

Devices not responding after C7 to C8 Migration

Just positioning: @gopher.ny isolated and solved the bug trough the last firmware update, everything is working now. I would like to publicly thank Victor for the fast response and solution!