Certainly not your network connection to the external World with those numbers.
You said this happens in the basement. Is your wifi router in the basement also or upstairs? Basements are notorious for dead spots when the wifi router is not in the same area. Consider an app like wifi sweetspots to map out the wifi functionality throughout the basement.
Testing wifi calling function in other areas of the home and with other wifi locations around town would be interesting to see if the same thing happens.