KB5033375, also known as Windows 11 December 2023 Update, is a mandatory security update that fixes several bugs. However, Windows 11 KB5033375 is also proving to be a disaster for some people. According to several reports seen by Windows Latest, the December 2023 update could break some Wi-Fi connections.
Our readers, particularly those working with universities or small to medium-sized businesses, have been experiencing slow Wi-Fi speeds after installing Windows 11 update KB5033375. The issue seems to affect everyone with more than one wireless access point, a common configuration in universities.
A user running Windows 11 22H2 told us their Wi-Fi quality degraded to such an extent that they have trouble even when sending ping requests to Google. The responses were inconsistent, with half of the requests failing to resolve and the other half suffering from substantial packet losses and delays.
Microsoft hasn’t commented on the reports, but users told us that the issue was first spotted in an optional KB5032288 update, and it has also slipped into KB5033375, which is a mandatory update.
The bug seems to be affecting at least two updates released in December – KB5033375 (mandatory security update) and KB5032288 (optional update).
Some believe the issue is limited explicitly to Qualcomm’s old wireless adapters, mainly used in public universities.
Universities recommend uninstalling Windows 11 update
In support documentation, the University of New Haven warned that “a recent Windows update released on 12/12/2023 has caused users to not be able to connect to the wireless networks. This update is known as KB5033375.”
Similarly, the University of Brunel London confirmed that the Windows 11 December 2023 Update could be a deal breaker if students want to access the Wi-Fi on campus.
“If you have a Windows 10 or 11 laptop and recently downloaded a Microsoft update, you may have difficulty accessing the Wi-Fi on campus,” the university warned and recommended students uninstall the update if they have exams in the coming weeks.
One of our readers, who works as a system administrator at a university, identified that the issue could be linked to a compatibility problem between the Qualcomm QCA61x4a wireless adapter and the Windows update. However, that’s not entirely true.
While the bug does affect Qualcomm adapters, the issue could be linked to broken PEAP (Protected Extensible Authentication Protocol) settings in Windows caused by recent updates. As some have observed, the problem affects Wi-Fi connections using PEAP.
A thread on Microsoft forums suggests that Wi-Fi problems occur on WPA2 Enterprise SSIDs when used with 802.11r. Disabling 802.11r appears to restore connectivity, but this is a less-than-ideal solution due to roaming issues.
The issue seems widespread, with reports from various universities and educational institutions.
How to deal with Wi-Fi issues caused by KB5033375 update
The quickest workaround is to switch to EAP-TLS from PEAP. This is an alternative to password-based authentication.
You can also turn off 802.11r on the affected SSID, as the root of the problem appears to be in the 4-Way Handshake, but that won’t be an ideal solution.
If you’re unable to upgrade your wireless adapters, you might want to uninstall the update using Settings or Command Prompt.
Microsoft hasn’t acknowledged reports of Wi-Fi or PEAP issues in Windows
Microsoft has not acknowledged or offered a fix for this issue, but my sources tell me the company is already looking into the reports.
Windows 11 December 2023 Update is the last update of the year, and it is a significant release for several reasons, including Copilot improvements.
This update improves the Copilot experience on the desktop with support for multiple displays. This means you can now open Copilot wherever you want, the primary or the secondary display, by clicking its button on the taskbar.
In the release notes of the last preview update, Microsoft explained that the thumbnail preview for Copilot will be visible when you switch between apps and Copilot. This is similar to Microsoft Edge and other web apps appearing alongside traditional apps.
While the December 2023 update sounds decent on paper, it could be a deal breaker for some people.
Update: In an update to its support document on December 19, Microsoft confirmed our findings on Wi-Fi issues and announced that it has already rolled out an update. This server-side update fixes an issue causing Wi-Fi network connectivity problems on non-home devices, particularly enterprises and universities.