Yes, VoWiFi service is active and verified by provider (I asked their support).
What is enough to tell phone to try initiate VoWiFi connection again? Toggle Flight mode, WiFi or reboot?
12:54:07 wireless,info [AP-MAC]@wlan1_CL: lost connection, no beacons received
12:54:08 wireless,debug wlan1_CL: must select network