WiFi Now Keeps Disconnecting on Second Device

I am using Xfinity Wifi Now Hotspot for internet until I can get another job. I use it on my computer and phone. However, the phone keeps disconnecting from wifi at certain times of the day and night. When I try to reconnect, I get "connection failed" or "Cannot connect to IP."  Is this a typical occurrence? What's the point of offering two device connections if one of them is being throttled at certain times?