ASUS RT-AC1900P and low speed on iOS via WiFi

I’m using an Asus RT-AC1900P router linked via Ethernet (Cat8) bridge to an identical RT-AC1900P and for the life of me I can’t establish a solid WIFi network that will download more than 80Mbps on 2.4 GHz and 200Mbps on 5Ghz on any of my Apple devices (Apple iPhone XS Max and a 4th Gen iPad). When I hard wire my MacBook into my router I get 450-500Mbps Down, which is not nearly as fast as the advertised 600Mbps but still much better than 200Mbps. I tried changing channels, I tried extending...

ASUS RT-AC1900P and low speed on iOS via WiFi