I can’t replicate a fundamental issue - last few days the FP3 will continously make wificalls, no modem firmware crash or the like that’d necessitate a reboot.
At times it used the radio instead of wificall, but could be up to my provider (it was nationally roaming when it chose gsm).
Haven’t yet a grip on understanding where Android components decide either way:
If you want to look yourself, it’s
adb logcat Telephony Telecom Dialer SubscriptionUtil ImsCall QImsService *:S
and add a filtering pipe at the end for what is an indicator how the phone sees it
| grep -E '(isWifi: [YN]|isWifi=[a-z]+|isVoWifiEnabled=[a-z]+)'
but *#*#4636#*#* is as truthful if VoWifi is available and its register status known.