Glad you made this observation because it could help finding the true reason for the annoyingly long network pause after each call.
It is about the same time when I got my Xperia 10ii and t-mobile canceled 3G. Therefore I might have wrongly assigned the long network loss after every call to the switching-off of 3G - and not to SFOS/aarch64. I will check with my older back-up XA2 in order to confirm your observation