Are you using Smart Connect?
Are you going through any type of Wireless Access Point, such as an AiMesh device?
Is your bandwidth being split with another device or devices?
Have you changed any of the default settings on the router?
Have you been able to test internal network speeds, like putting another system on the 2.5 Gbps port to your system?
If you were to have a Dell system, I would ask about SmartByte..
I think my Z490 board had an Intel AX201 card and I don't remember it having a problem..
You have or have not used Ethernet to verify your expected speeds?
I'm facing almost identical issues to you. Since purchasing the Ax11000 and currently now with Bell 8gb speeds.from 3gb. I can't get past 700mbps max I've ever hit on the Ax11000. The Bell Giga Hub on wifi 6e near the modem on my S23 ultra hit 1.7gbps
Just wondering since not much seems to be happening, is the speed always at exactly 700 Mbps or does if vary from that number? I might think if it always went up to but no faster that, something was limiting the speed.. If it were moving around, like 300 up 700 Mbps, that might mean something else is sapping your speed..