wifi hostname issues

In the past couple of days, I have issues staying connected on wifi with two of my devices running iOS 14.1. I will be connected to the wifi and then, when the phones wake from sleep, the wifi drops and then reconnects automatically. I've already done a factory reset on one of the phones to eliminate software issues. 

Additionally, for one of the phones having wifi issues, the XFi modem seems to be randomly assigning new host-names to me iphone. Instead of just saying Neil's-iphone, it assigns random numbers (Neil's-iphone-3, neil's-iphone-220, etc). The MAC address and the IP address remains the same. This is the only device for which the modem appears to be doing this. 

I'm not sure if these issues are related or not, but appreciate any advice. CAlled Comcast and they restarted the modem, did some diagnostics, etc., but didn't have any further specific advice.