Desktop PC, USB 2.0/3.0 ports, Windows 10 Pro updated, desktop about 3 years old

Using AX1800 - Archer TX20U-Plus - hardware version is 1.6

Adapter plugged into blue 3.0 port.

Using fast.com and speedtest.com speed is 25Mbps up and 15Mbps down.

downloaded latest drivers from TP-Link; no change in speed

downloaded Dell Support Assistance, ran all scans, update OS, software, and hardware - no change in speed

other wi-fi devices, including my laptop, are getting 300+Mbps;   access point is 10' away

Suggestions?

Thanks!