Performance with Nighthawk Mesh system... MR63

Hi there - I just installed the NH MR63 kit, with the router and two satellites... The purpose of me doing this installation was to get better coverage in my three-story townhouse, as my single (ISP provided) wifi router wasn't reaching reliably into the third floor.

I updated all the firmware on all the netgear nighthawk router and satellites to current. (V1.0.6.102_2.0.45)

So I was excited to install a WiFi6 system, as the ISP Wifi Router (Hitron CODA-4582U) was a AC router. I have only one device which supports Wireless AX (my son's gaming computer).

The service I have is 1Gbps down, 30Mbps up. Router is installed on the ground floor right beside the old Wifi router. Wifi has been turned off on the old router for testing. (Which I later turned back on with a different SSID to test the difference)

Previously, the gaming rig (installed on the 2nd floor, immediately above the ISP router - so about 10' away through a floor) would get download speeds of about 600-620 Mbps down, and the full 30Mbps upload (Measured multiple times using Speedtest by Ookla.)

After installing the NH MR63, I get download speeds maxing out at an average of 41.94 Mbps, and uploads of 31.40 (pretty much normal upload).

My question is simple - why after 'upgrading' to the Wifi 6 system is my download speed only 6.6% of my previous experience?

If I turn on the old Wifi router and connect to it, I'm back up to the previous speeds.

This seems really odd, and not what I expected at all.

I downloaded a free basic spectrum analyzer(Acrylic WiFi home), and noticed something odd, too.

The max connection speed reported by the OLD router was 216.7 Mbps on the 2.4 GHz channel, and 1733.4 Mbps on the 5GHz channel.

The max reported connection speed reported by my Nighthawk mesh system is 542 Mbps (I assume on the 2.4GHz frequency because on the new one, I'm using a single network name for both frequencies), and 1134 Mbps on the 5GHz frequency.

Why is the newer Wifi 6 router reporting lower speeds and connecting and downloading significantly lower than a three year old Wifi 5 / AC router?

For reference, the Nighthawk router is on the ground floor, 10 feet through the floor from the gaming PC, there is a satellite 15' away on the same floor through a wood/drywall wall, and there is another satellite 12' on the third floor right above the gaming PC.

If I check the connection properties (connected to AX router) in Windows 10, it shows:

SSID: [edited]
Protocol: Wi-Fi 6 (802.11ax)
Security type: WPA2-Personal
Network band: 5 GHz
Network channel: 153
Link speed (Receive/Transmit): 817/735 (Mbps)
IPv6 address: xxxxxxxxxxxxxxxxxxx
[edited]
Manufacturer: Intel Corporation
Description: Intel(R) Wi-Fi 6 AX200 160MHz #2
Driver version: 21.90.3.2
Physical address (MAC): [edited]

If I check the connection properties on the OLD router in Windows 10, it shows:

SSID: [edited]
Protocol: Wi-Fi 5 (802.11ac)
Security type: WPA2-Personal
Network band: 5 GHz
Network channel: 149
Link speed (Receive/Transmit): 866/390 (Mbps)
IPv6 address:[edited]
Manufacturer: Intel Corporation
Description: Intel(R) Wi-Fi 6 AX200 160MHz #2
Driver version: 21.90.3.2
Physical address (MAC): [edited]

Lastly, I can report that I have clear Wifi signal on all three floors of my house, but the Wifi speed is not up to what I was anticipating, especially with the single AX device in the house.

Any thoughts, insight, etc?