Hi!
This is the first time I have used an ISP supplied modem/router and I am getting terrible wifi coverage. I have four Eero Pro 6e devices hardwired into the modem/router and the wifi I am getting from the Eeros is terrible. Funny enough, the wifi I was getting directly from the ISP modem/router was pretty good, but had poor range. Now I have both networks set up and I think they are interfering with each other. I have used these Eero devices in the past in a much smaller apartment with a modem that didn’t have wifi. Any thoughts? Sincerely appreciate the help.
ISP supplied routers are generally garbage. Try and see if the ISP router can be put into bridge mode and see if that solves your issues.