I’ve found the culprit!
One of the Honeywell evohome thermostats was apparently low on battery and caused an RF storm in the same frequency. I’ve had this on evohome system once before (6 years ago).
They operate on the same wavelength and will block all RF signals also for Zwave.
6 years ago I replaced most of the thermostats but this room we hardly use and I forgot we had this old thermostat still operating there.
It was a coincidence that the homey 12.2.1 update went live at the same time the battery went low. Unfortunately the Honeywell evohome system does not indicate the low battery otherwise I would have spotted an offline device.
Sorry for any trouble at support. I will close the ticket now.
