Qualcomm Atheros QCA61x4A (Driver 12.0.0.1257) on Windows 11 negotiating only 173 Mbps instead of 866 Mbps

DANIEL 0 Reputation points
2026-07-20T19:04:22.59+00:00

Greetings, everyone.

A few weeks ago, my Wi-Fi connection was working fine on Wi-Fi 5 using driver version 12.0.0.722. Driver version 12.0.0.1257 would only give me around 40 MB/s throughput, so I rolled back to .722 and the issue was resolved. This was on Windows 10

Last week, my PC upgraded itself to Windows 11. Since then, even though nothing else has changed (same router, same distance from the access point, same connection, same device), my link speed has dropped dramatically. The maximum receive rate I can get now is 173.3 Mbps.

At first, I thought it was a driver issue because Windows automatically updated the adapter to version 12.0.0.1257. However, after testing several driver versions (.722, .953, and .1257), the receive rate remains exactly the same.

At one point, I uninstalled and removed all the other OEM driver packages, leaving only one driver installed. After doing that, the adapter suddenly negotiated at 866.7 Mbps again and everything worked perfectly. Unfortunately, after restarting the PC, the adapter failed to start and showed a Code 10 error. I had to restore the system to get it working again.

Since then, I have tried multiple drivers, clean installations, and even forced driver versions manually, but I have not been able to get back to the 866.7 Mbps link rate.

At this point, my main suspect is the Windows 11 upgrade itself, especially because several advanced adapter settings that I used to have access to seem to be missing now.

Has anyone experienced something similar with the Qualcomm Atheros QCA61x4A adapter on Windows 11?

My laptop is a Lenovo IdeaPad 3 15ALC6.

Any help would be greatly appreciated.

Windows for home | Windows 11 | Internet and connectivity

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  1. Hendrix-V 20,785 Reputation points Microsoft External Staff Moderator
    2026-07-22T07:00:42.7766667+00:00

    Hi DANIEL,

    Since the adapter is connecting at 173 Mbps instead of the expected higher 802.11ac speeds, this is often related to how the wireless connection is being negotiated rather than the internet service itself.

    Please feel free to check out Alvise answer first then have a look with my answer

    You may want to check the following:

    1. Make sure the PC is connected to the 5 GHz Wi‑Fi network and not the 2.4 GHz band.
    2. In Device Manager > Qualcomm Atheros QCA61x4A > Properties > Advanced, verify that 802.11ac mode is enabled and the Preferred Band is set to 5 GHz (if available).
    3. Check your router settings and confirm that 802.11ac and 80 MHz channel width are enabled.
    4. If the issue started after installing driver 12.0.0.1257, try the latest Wi‑Fi driver available from your PC manufacturer's support page, as vendor-specific drivers can sometimes provide better compatibility than a generic driver.

    If the speed remains capped at 173 Mbps, please share your PC model and router model, as that can help identify whether the limitation is coming from the adapter configuration or the wireless network setup.

    I hope this helps point you in the right direction. Let us know what you find, and the community can help with the next steps. Thanks for your effort.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

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  2. Alvise Cervellati 6,975 Reputation points Independent Advisor
    2026-07-20T19:48:56.5833333+00:00

    Hi Daniel, Welcome in Community

    Ok, this is the latest version available on Lenovo support website, now follow these steps for reset completely the network and other stuff:

    Press WIN + X and open terminal as admin, now type

    netsh int tcp set heuristics disabled

    netsh int tcp set global autotuninglevel=disabled

    netsh int tcp set global rss=enabled

    netsh winsock reset

    netsh int ip reset

    ipconfig /release

    ipconfig /renew

    ipconfig /flushdns

    Restart the system

    Also, in your system is installed Killer performance suite of Intel?

    Let me know

    Elvis

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