Hello I am facing high drop with Volte calls when no 4G coverage and according to the operator , it is not network issue , my handset Samsung S23 ultra does not support Volte SVRCC even it has VOLTE ? is this correct that some handset support Volte but does not support SRVCC?
Hello @Ayat_Shabash
Start the analysis from the MME side, as some messages may not be sent from there (in the classmark message, for example, i.e).
But there is a chance that this problem appears due to an error of the phone itself.
Try to take another similar phone and test it. If the same situation happens again, contact Samsung support.
Hello @Nekto
Yes, other phone like S22 is working, and I contacted 2 Samsung.
I got non technical answer that, yes there some model does not support!
Do I have to wait Update or buy new handset? 
OK!
It seems to be and Samsung S10 have a problem with HO too…
