That's how it i supposed to work.
There is an issue with your port or your individual device.
But as @MrT10001 told you it's best to follow the instructions as it has been tested by others and the experience is understood and known.
When you go off rails or do some unsupported actions then you're basically on your own.
People told you to follow instructions, you ignored the advice so it's impossible for us to determine whether it was your own doing or a legitimate issue with the port.
Bug analysis is now on you 🤷
About VoLTE there are still some work to do. It's almost there for Mediatek devices but there is still work to do for Qualcomm's.
If I had to guestimate I'd say it will be widely available mid-2025.
But no promises, development is hard to predict.