I'm getting a lot of dropped incoming calls on my S9 when using WiFi calling. It usually happens during the 1st minute of the call. After a drop, the phone shows that I missed a call even though I was able to have a good two way conversation for a period of time with the caller before the drop.
I'm in zipcode 30120 with a weak 4G signal so i use WiFi which is a good reliable signal.
Outgoing calls don't seem to have the same problem