Since WiFi Calling was working fine and only recently became a problem, and given all the things you've already tried on your phone to fix it, the actual cause might not necessarily be with the phone. As
@Dannydet suggested, try restarting your router. I know you mentioned your home WiFi is apparently working OK but basic networking isn't that simplistic -- each and every device connected to your home network is its own connection to a central gateway (your router) so just because other devices are OK that does not automatically mean there isn't a glitch with the connection to your S10e. Or in other words, the problem to focus on is with your S10e, not the other devices in your household. Anyway, just restart your router -- that might fix the problem but if it doesn't you can at least eliminate your home network as a suspect.
If WiFi Calling is still a problem, can you tried connecting your phone to a different WiFi network (i.e. neighbor's or at work) to see if that does or doesn't make a difference?
