Windows 11 Patch Day: KB5089549 update now causes frustration on the PC

Error messages, installation cancellations and painfully slow internet: The Windows update KB5089549 is currently causing some PC owners more frustration than greater security. Conflicts with virus scanners and BitLocker make the May patch a problem.
Problems with Windows Patch Day
Security update KB5089549 for Windows 11, which is routinely released on Microsoft’s regular May Patch Day, is causing problems. For some users it becomes a challenge because the installation does not work and breaks off repeatedly. So far we haven’t heard anything about problems from Windows support. However, this is not unusual so soon after the patch has been released.
Affected systems will display an error message during reboot stating that the changes will be reverted and the update cannot be applied. A possible cause of the crashes is incompatibility with third-party antivirus software such as Avast. Also circulating reports of conflicts with the BitLocker encryption software.
Other errors appear
In addition to the installation hurdles, another problem arises. As Neowin Reportes, the update is slowing down internet connections for some users. The network problem occurred for users immediately after successfully installing the update for Windows 11 version 25H2. The exact technical reasons for the drop in performance in the network are currently unclear, but it is being discussed Microsoft Forums already discussed.
Possible solutions
System administrators recommend the following steps when network speeds are reduced: updating the network interface card drivers through the hardware manufacturer, resetting the TCP/IP configuration using the command prompt, and checking the advanced adapter settings for default values. If the measures mentioned do not bring any improvement, the only option is often to uninstall the update manually. After that, it is recommended to temporarily pause the automatic update until an official fix is available.