Thanks Floppus, for me it seemed the Zigbee network did not even start (driver could not be loaded).
In the meantime the Homey does not even start up anymore it seems: not LED ring lighting up when the power goes in, only some buzzing noise from the speaker when I put my ear next to it.
@robertklep I’ll contact Homey, hopefully something can be fixed still. Also have no backups. 
