VoLTE on ROG 5S in Australia (Telstra and Optus)

[crisisxcore]

Please tell us some basic information before asking for help:
Model Name: ROG 5S
Firmware Version: 31.0810.1226.91
Rooted or not: Not rooted
Frequency of Occurrence: Ongoing
APP Name & APP Version (If your issue relates to the app): VoLTE
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.
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ROG 5S 512GB model in Australia.
When it was on Android 11, special code was required to enable VoLTE (Shows as "Call on 4G" in setting) - VoLTE did not work. Network drops from 5G to 3G when on call.
After upgraded to Android 12, "VoLTE" option is available in setting without special code - VoLTE still does not work.
Some reported that VoLTE works without issue in Australia with Telstra (Telco).
My previous devices such as iPhone 11Pro Max, 13 Pro Max, Galaxy Z Fold 2 and 3, Pixel 6 Pro had no issue with VoLTE with same SIM card with same service provider - Telstra.
Can someone confirm if this is the issue with the device or VoLTE does not work with Telstra? Because VoLTE works with Optus.

[FunBike31]

VoLTE and Asus is a great love story but marriage is not for tomorrow and at the current speed of adding compatibility with operators either there will be a miracle before 2025 (end of 2022 in the USA) or Asus will no longer sell phones.
I assure you, your Phone is not broken, just Asus playing with fire by not giving an obsolete priority to extend VoLTE compatibility with operators, who on their side are respecting the 3G shutdown schedule. that they announced.

[crisisxcore]

Thanks for the comment.. I just want to check with other Telstra user with ROG5S because someone in Zentalk said VoLTE is working with Telstra - Thank you ASUS for implementing VoLTE & VoWiFi for Telstra, Australia in Nov 2021 Firmware Update — ...

[FunBike31]

Yes, I remember it well because my niece was in Australia and wanted to buy a zenfone 8 for its size, but given the absence of VoLTE and the predictable heating of the SOC, she followed the path of reason with an iphone 12 mini .
You just have to hope that the loss of VoLTE with Android 12 is only temporary and that ASUS will ensure this compatibility before mid-2024 😞

[crisisxcore]

VoLTE was not available with Android 11 as well. I would understand if I imported the device, but when ROG 5S is officially sold in Australia...