Similar question here:
Iam using Leeco S2 (x526) with newest /e/ 1.8 (Android 10/Q)
There is no option in telephone or system - settings to activate volte or vowifi.
When dialed * # * # 4636 # * # * (USSD-Code), the volte and vowifi was checked out and there is no possibility to move checkbox to active.
also IMS Status (same menu) shows that everything is disabled
I tried editing the build.prop according to xda developers thread:
So I started TWRP and edited build.prop via TWRP file manager/editor
persist.dbg.ims_volte_enable=1 (already exists)
persist.dbg.volte_avail_ovr=1 (already exists)
persist.dbg.vt_avail_ovr=1 (already exists)
persist.dbg.wfc_avail_ovr=1 (does NOT exist → added manually)
persist.radio.rat_on=combine (already exists)
persist.vendor.radio.data_ltd_sys_ind=1 (already exists, but with “vendor”. In XDA, it is without “vendor”)
persist.vendor.radio.data_con_rprt=1 (does NOT exist → added manually including “vendor”)
persist.vendor.radio.calls.on.ims=1 (does NOT exist → added manually including “vendor”)
I do not know what the “vendor” is good for. As the other entrys are named “vendor”, I added to the missing entrys “vendor” too
Afterwards I rebooted and when opening Android settings menu, I got immediately asked if I want to enable wifi-calling.
when dialing * # * # 4636 # * # *, the checkboxes are enabled now. But when checking IMS-Status, it is shown as “not registered, not available”
I also added “ims” to “APN-type” in APN settings.
My carrier (o2-Germany) officially supports vowifi/volte and the sim card is quite new.
still no vowifi/volte