WiFi speeds dropped from 400+ to 30-100 Mbps after clean Windows 11 install, every other device on the network is fine
So I just did a clean install of Windows 11 Pro on my PC and my WiFi speeds dropped significantly. Before the reinstall I was consistently getting 400+ Mbps on 5GHz. Now I'm stuck at 30-100 Mbps on the same network, same router, same physical location.
My setup:
● Intel Wi-Fi 6E AX210 (PCIe card)
● ASUS ROG STRIX B550-A
●Ryzen 5 5600
● Router: CODA4582 (ISP provided, channel 36-40-44-48, 80MHz, 802.11 a/n/ac mixed).
● Every other device on the same network gets 400+ Mbps.
What I've tried:
● Latest Intel driver (24.40.0.4) — no change.
● Multiple older driver versions — no change.
● Uninstalling and reinstalling the driver from scratch.
● Changing roaming aggressiveness to lowest — made it worse.
● Verified region is set to USA.
● netsh wlan show interfaces shows 802.11ac instead of 802.11ax, reception speed ~97 Mbps, channel 36
● netsh wlan show drivers shows all bands as 0 MHz - 0 MHz which seems wrong.
● Changed router channel to 149 — speeds went up to 100 Mbps but degraded performance for all other devices so not viable.
Anyone seen this after a Windows 11 clean install? Feels like something in the driver or Windows is limiting the channel bandwidth negotiation but I can't figure out what.