I have the international version of the S10 Plus working well here in North America on T-Mobile except for a few minor bugs. The most annoying of those is the behavior of Wifi Calling.
Although Wifi Calling does work quite well, I have to put the phone in Airplane Mode and enable wifi to force it into Wifi Calling mode. I set the SIM to "Wifi Preferred", which should automatically switch to wifi when I'm on my wifi network. At first, it would switch to wifi calling when it first connected to my wireless router then would revert back to the mobile network after a few minutes. However, since the April 1 update, it completely ignores the "Wifi Preferred" setting behaves as if "Mobile Network Preferred" was selected.
As long as I remain in Airplane Mode with wifi enabled, it keeps a steady connection to Wifi Calling. The moment I enable the mobile network it switches back.
Has anyone else experienced this issue and, if so, how do I get this to abide by the Wifi Preferred setting?