Must UE send / request IMS PDU session in 5G SA?

Hi all 5G Experts.

For 5G SA, must the UE send / request IMS PDU session?

I see if on Core side IMS flag disabled, then UE isn’t attaching to the cell.

Only when IMS is enabled on 5G Core then UE attach to SA cell.
(This I see on Samsung UE S21 Qualcomm Chipset).

As phones are voice centric by default, if it doesn’t get voice (IMS) service, it won’t work normally.

I understand.

Another thing: only when I set UEs for NR only enforcement then UE connect and attach to SA cell.

If I don’t set on UE NR only by any enforcement APP at UE like to keep it NR/LTE/3G auto.

UE isn’t connecting to my SA cell only.
If I set it by enforcement APP for NR only then UE attach to my SA cell.

Without configuring UE by APP called 5G LTE force for NR only then UE will not even attach to my SA cell.

Please check NR / LTE cells frequency priority.

If LTE cells have higher priority than NR than UE will always select LTE first.

Yes but you can do this setting by qxdm as we’ll.
Make it by data centric enable.

Same thing I’ve noticed as well…