AC1200 wifi range extender and wifi calling issues

I set up the AC1200 wifi range extender tonight and things were going well until we could no longer use the wifi calling feature on the main wifi connection. It would only work on the _2EXT or _5EXT wifi connections. I tried turning the iphone 6 or 6s off and back on, switcing between wifi connections and turning wifi calling off/on on the phone. These did not work. Eventually once we unplugged the extender the phone switched back to wifi calling. However the extender is intended to be moved to the garage and I don't know how good the signal will be yet. We have to use wifi calling due to no cell signal at our home. Any thoughts on how to fix this?