My phone is an unlocked Samsung Note 9 and I am on the Verizon network. Make sure your phone as the latest update. Then from the Samung Phone Dialer app, not your Setting app, click it open. Then once the app opens you will see the 3 vertical dots. Tap those 3 vertical dots , click "settings" and then scroll down to the Wi-Fi slider. Hopefully is not shaded gray...if so, contact Samsung support. If is not, move the slider to the on position. You should be good to go. I had this same problem until I went to the Phone dialer settings feature.
Thanks, that worked! I have an unlocked Note 8, which I bought directly from Samsung during the pre-sale period. When I first found out that I could not enable WiFi calling in the phone settings I spent a lot of time contacting Samung (who sent me to Verizon) and Verizon (who sent me to Samsung) without any success.
Now, I am seriously considering getting a Note 20 Ultra, and was trying to decide between the unlocked and Verizon versions. Now that I know I can get WiFi calling on the unlocked version, that will be my choice (if I buy).
Well, not successful after all. I turned on WiFi calling in the phone app - and it remains on. But now I am in my basement, with good WiFi connection, and I tried to make a call: the phone says "Mobile network not available" so it doesn't work after all.
Any other suggestions?
This is especially disconcerting because I ordered an unlocked Note 20 Ultra last night.