I recently switched from AT&T to mint. Once I switched, everything worked out well, but my wi-fi calling feature is greyed out and I am unable to select it. I used a Android Galaxy S7 Edge. Wi-fi calling and text through mint is activated, but the feature on my phone is not available. It's unavailable when I go in my settings. Im assuming the AT&T software inside is causing issues, but any advice would be great.