@jben, would you be willing to try to dive into the TP-Link AC1750 specs to see if you see anything there that might be closing down MQTT or SIP after a period of time? Or maybe some configurable QOS settings to keep the phone prioritized?
Next, if you’re still game, would you mind creating a log the next few times you try this that provides the last 4 digits of the calling phone, the time of the call, the state of the G5+'s RW notification, any steps you took, and whether the call was successful.
From 1234 at 4/5/2020 10:33 a.m. ET, RW notification “cell calls”, after a period of inactivity, call fails.
From 1234 at 4/5/2020 10:35 a.m. ET, RW notification “connected to” my network, rebooted router, call succeeds.
I’d like to gather a few call samples, pull the device logs, and create a ticket on your behalf to see if our technicians have any insight.