We got bad Windows 11 news (again...)

The Windows 11 December 2023 Security Update is required and is designed to strengthen your security. However, according to user reports, it can lead to disruption of Wi-Fi on public networks.

The December 12 security update KB5033375 includes all of the improvements from the December 4 preview release of KB5032288, protecting your system from the latest threats. However, this patch unfortunately brings some problems for users. In the forums, they began to complain that this patch disrupts the operation of computers with Wi-Fi. The device still connects to the network, but there are considerable delays and packet losses.

Who is affected by the Wi-Fi problem?

As we mentioned before, the problem with the quality and speed of Wi-Fi connection also affects the earlier patch KB5032288, which is an optional update. It has been reported that problems mainly occur when using routers that are configured with the PEAP authentication protocol. This protocol is quite rare in the case of home networks, but is widely used in educational institutions, public spaces and businesses, that is, places with a large number of wireless access points. Wi-Fi connectivity problems occurred in a number of universities, including the University of Brunel London (UK), the University of New Heaven (US) and in a number of universities in Netherlands.

The good news amid the bad news is that these Wi-Fi connection problems do not seem to occur on all computers, but mainly on devices with certain Qualcomm Wi-Fi adapters, as well as those that support the 802.11r fast roaming standard. "We have two wifi networks one that has 802.11r (Fast BSS transition) enabled and one where it is disabled. The students only have this problem on the enabled Fast BSS Transition wifi network," wrote in the Reddit forum an IT administrator of one of the universities in the Netherlands, where there were failures in connecting to Wi-Fi after installing the patch.

However, there is not yet enough information about all cases of connection failures to make an accurate diagnosis about what kind of equipment this problem occurs on, and whether it even depends on the brand and type of equipment. There have also been reports of connection failure on MediaTek devices, so it is too early to draw conclusions. In addition, so far we have not had any reaction from Microsoft itself, despite the fact that the corporation itself probably could not help but hear about the problem with the patch.

What should I do if my Wi-Fi connection is lost after installing KB5033375?

The schools and universities mentioned above advised students to uninstall the KB5033375 and KB5032288 updates if they encounter any problems with Wi-Fi connection on computers running Windows 11. You can also, as a temporary measure, uninstall these updates, but you need to understand that after this you will also reduce the security level of your device. Another solution may be to try to disable the use of the IEEE 802.11r-2008 standard in the network settings.