Recently VoWiFi stopped working for Telstra/Boost Australia

[noldoli]

Please tell us some basic information before asking for help:
Model Name: ROG 5
Firmware Version: WW-31.0810.1226.139
Rooted or not: Not rooted
Frequency of Occurrence: Always
APP Name & APP Version (If your issue relates to the app): Phone calls
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
========================================
For almost a year (from ~Nov 2021 till ~Oct 2022 or so this year), with Australian mobile carrier Telstra (and by extension its retail MNVO, Boost), ROG 5 used to work very well with VoWiFi (aka WiFi calling). Then recently, it's stopped working. (VoLTE still works though; so the problem is limited to VoWiFi only at this stage.)
Can this problem be fixed ASAP please? This is an essential functionality of a phone for me.
Living in an outer suburb with terrible mobile signal coverage inside home, this is causing me grief (in terms of mobile call quality being terrible and unreliable). When VoWiFi was working, due to being connected to strong WiFi network based on a fast/reliable fibre Internet connectivity, phone calls inside the home used to be always great. But not anymore!
I've proven that the SIM itself delivers VoWiFi on a Motorola Moto G 5G phone. So SIM and mobile operator are clear in this case.
(I'm asking around for Optus & Vodafone-TPG SIMs to see whether this VoWiFi breakage is limited to Telstra.)

[noldoli]

@CH_ASUS @Titan_ASUS Could you please read this thread? Can you please DM me to receive the Google Drive link for the log file? Would you be able to share it with your folks? Thanks

[noldoli]

The link for the log file has been successfully submitted.

[Eraly]

I can confirm this same scenario on the ROG 5s. but not even Volte works.

Was disappointed to have bought expecting these features October last year when reports said it was working.

Happy to provide additional information for fix if required. 

[noldoli]

Time is of the essence. The recent update from end of Jan still has this problem unaddressed. As time rolls on, this phone is in danger of becoming an expensive paperweight. I've learnt my lesson not to buy another Asus phone, even when at some point it works well with all essential functionalities (like VoWiFi), as history has shown with this phone, it's likely to break later on & worse yet, may never get fixed.

Motorola phones seem not to suffer from this sort of carelessness, indifference towards their customers etc. So purchase of Asus phones for one who cares for essential functionalities (behaving like a good phone), is something I can't recommend to anyone in good conscience. Aside from VoLTE and VoWiFi working on Motorola phones, they end up costing a lot lesser than Asus's (i.e., saving heaps).

[noldoli]

Another update & another missed opportunity 🙁. The late April update still hasn't fixed this issue. No VoWiFi yet with ALDI/Boost (both Telstra MNVO). The frequency of updates has obviously significantly slowed down lately. So rarely does this phone receive updates. So, now there's no hope that ASUS would ever care to fix this problem. I put my money where my mouth is by purchasing non-ASUS phones -- Motorola a while ago & recently OnePlus 11 5G. Once bitten, twice shy. Obviously, I won't be buying another ASUS product. In my sphere of influence, I've been persuading others from avoiding ASUS products since the breakage of this essential functionality (VoWiFi) with my carrier of choice.