M2 Max MBP16 internet connection

First, this is on Ventura, not Big Sur, and yes, everything is updated. I recently purchased the M2 Max MacBook Pro with 96 GB of memory. I also recently purchased Comcast Xfinity internet and opted for their 1200mbps/1.2gbps plan, with their xFi Complete 6E modem/router.

When I’m in the same room next to the router, every speed test is showing speeds exceeding 1.3gbps on the MBP. But unfortunately when I’m in the next room, only roughly 15 feet away, I’m unable to connect AT ALL. So much that the speed test states that it can’t even do a test because I’m not connected.

the unusual thing is, both my iPhone 11 and Hermès Series 8 can connect in the same exact location in the next room. A speed test and comparison in the two rooms on the iPhone is a difference of an average of 400mbps versus 750mbps, which I can live with. I always thought the WiFi cards were superior in a MacBook Pro when compared to an iPhone, especially a MacBook Pro that supports 6E/ax. The iPhone 11 certainly does not, yet is able to connect with relatively good speeds, although only roughly half.

I understand that the modem/router they supply is inferior compared to a new Arris Surfboard modem and a new Asus router (only reason I opted for the rental is because of the unlimited data without throttle). But this much of a difference, with a 6E router? What are the chances that I got a faulty wifi card in my M2 Max MBP? I have a feeling I’m going to get a lot of finger pointing. Apple is going to say it’s Comcast Xfinity’s equipment, and they of course will say it’s the MBP16. Is there any way I can test the WiFi card in the mac, or run a diagnostic on it?