Same issue here. Switched to XM from ATT. WiFi calling worked flawlessly on ATT. Ported one phone, purchased other from Xfinity. Both iPhones. Both have same issues when calling from WiFi. We only have one bar of cell at our home. Very strong wifi, 300Mbs, good coverage throughout home. Used ATT with same wifi, no problems. ATT Carrier settings allowed you to move from cell to wifi but would not move call from wifi back to cellular.
Calls Fail when initiating call. Call drops during conversation on most calls from WiFi.
Surprised this is happening since XM says they will move your call to hotspot to save on cost.
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