Added several devices and wifi speed my orbi mesh system has plummeted

Hi,

I have had 2 cam v2 forever and recently upgraded to ATT fiber 1gbps service with my orbi router system w 2 satellites. After the upgrade i was getting around 400 mbps on my wifi speed test and just testing the router itself, i would get 900.

I added a floodlight cam v3 along with a outdoor base (hardwired) and 2 outdoor cameras, and now the speeds over wifi are down in the 40-80 range down, 30-60 range up. A friend told me he had the same experience with his wifi6 orbi (the newer system than mine) after adding multiple wyze cams.

This weekend i wanted to add a security system and a doorbell camera but am now worried what that might do to my speeds. The ATT modem has its own router built in, that still gets around 400. My desktop still gets 900 hardwired directly to the modem.

Anyone have similar experiences or any suggestions? Thank you!