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).
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.