Thanks everyone. Play Services version is 24.41.34. Battery usage was previously set to "allow" (I don't see a setting to say specifically "unrestricted" but would interpret this as unrestricted). Mobile data had "Background data" enabled, however did not have "Unrestricted mobile data usage" allowed so I changed that and rebooted the phone. Unfortunately I am still in the same situation. My old iphone 8 will still ring with the MySudo app (on wifi) but unfortunately the sim card from my Pixel 7a does not fit in the iphone 8 sim card tray. Guess I'm stuck trying to figure it out or reverting the Pixel to a stock Android distribution (not my preferred solution).