A quick update for future reference: on HP23 an acceptable way to change the channel is to choose “Reset Zigbee” from the developer page, repeat until Homey selects the channel you want. All devices will still be present, but in failed state. You can then repair them one by one. That may take a while, but at least it doesn’t break any flows or insights.
I recently changed from CH11 (interference with neighboring APs on Wifi CH1) to CH15 and that solved a lot of zigbee stability issues (mainly missed motion and stopped reporting). It took me about an hour to re-pair 60 zigbee devices.
BTW: Restoring a backup does not work, the backup contains the Zigbee channel setting as well.
Update 2w later I am experiencing the same isues again (delays, devices not responding and even dropping from the network). unfortunately the wifi utilisation in the neighborhood seems to have changed, causing interference on Ch15 again. I am going to try to set Zigbee to CH25 and see if that solves it once and for all.
