its not that i couldnt get it to work. i didnt work for my requirements. i need the ax3 that connects directly to my router to be in AP mode and the mesh doesnt work if thats the case. might give the mesh thing another go when im in a bigger place and have fttp. but for now im on a 5G connection and have another 5G failover so need to use my ERX and external modem setup.I struggled a lot to start with getting the mesh going. I think I was trying to be to clever with settings, and got so annoyed that I just factory reset them all and followed the simplest instructions possible.
It worked straight away, even moreso when I redid it from scratch recently to have the quad core as main, it literally took minutes. So I'd encourage you to try again if you can bear to.