Wifi download speed

I have fiber gig connection plan and when I run the Xfinity test to my gateway the result is that I'm getting 120% of plan. I ran multiple tests using different speed test sites on both my laptop with an ethernet direct connect and on my iPhone 12 on WiFi. On my laptop I received a low of 205mbps and a high of 693mbps (the low 205 speed was an outlier) so I have no issue with that connection. However, on my iPhone 12 standing directly in front of the gateway  so there is no interference, I received a low of 32.8mbps and a high of 58.9mbps. I also have an AT&T fiber plan of 500mpbs. With my iPhone connected to the AT&T WiFi I received a low of 326.5mbps and a high of 398mbps. The 2 gateways are situated side by side. 

I have 6 pods situated at various locations in a 2-story 3100 Sq Ft house. Since I'm getting less than 60mbps standing directly in front of the gateway, I'm lucky to get 30-40mbps throughout the house. It seems the Xfinity gateway is not providing a strong enough WiFi connection. I have rebooted the gateway several times without any change in the WiFi speed. My AT&T plan is half of the Xfinity plan but the AT&T gateway is delivering WiFi speeds 6 to 7 times that of the Xfinity gateway. 

Any suggestions on what is going on?

Tony C.