ERROR: ISP's DHCP does not function properly

This error (and subsequent connection drops) occur almost hourly, and sometimes more often. It has been happening for months. I have tried all of the suggestions I could find in these forums and others. I use my personal Arris SB8200 modem with WAN aggregation on, going to an ASUS RT-AX88U Pro router (also WAN aggregation on). I have a 1.2Ghz plan. I have tried resetting the modem and re-activating the device through the Xfinity app, factory reset on the router, DHCP Query Frequency setting changes, MAC cloning, etc. NONE of these methods has done anything to remedy or improve the situation. Hardware-wise, nothing had changed on my end when the error started happening.

HELP PLEASE!!!