I am getting less than 1Gbps download and 1.5Gbps upload on a 3Gbps subscription on wifi.

I have a Telus Arcadyan NH20A with 3Gbps up/download wired with a CAT7 cable to a Deco BE85 10Gb port that is set as main router. From the main router, I used the 10Gb port connected to a 5-port 10Gbps Ethernet switch. From the 10Gb switch wired backhaul to 5 more Deco BE85 all with either CAT 7 or CAT 8 ethernet cables.

I was able to get close to 3Gbps upload and download speed with direct cable connection to the Deco 10Gbps port using a 5Gbps ethernet adapter on my laptop testing all 6 BE85. So, I know my internet provider is giving me the 3Gbps speed that I paid for. All the 10Gbps port is getting the 3Gbps connection speed

However, I was not able to get the WiFi speed close to it. The best speed I've seen is around 1170Mbps Download and 1557mbps Upload. I have tested using my Samsung S25 Ultra, Samsung S10 Ultra tablet and my Asus Zenbook S116 laptop all within 10 feet of each Deco. All 3 devices have WiFi 7 capabilities. I have tried setting the Deco to QoS to 10000, switching to different WiFi channels with no improvement of speed Currently, my 6GHz is set at 320Mhz channel 181

What did I miss? I need some help on it. Thank you in advanced