The recent mandatory cumulative Patch Tuesday update for Windows 11 may be causing speed issues with L2TP/IPsec VPN connections. Microsoft says it is currently investigating the problem.
End users may be experiencing speed issues with their L2TP/IPsec VPN connections after the recent cumulative Patch Tuesday KB5026372 update. According to a comment by a Microsoft employee on Reddit, end users are not having problems establishing an L2TP/IPsec VPN connection, but connections are very slow and RDP time out is being caused.
The problem is said to occur mostly on wireless connections running over Wi-Fi. On wired connections, the problem would not occur.
Problems already known
The speed problems in L2TP/IPsec VPN connections already came to light after the release of the optional non-security update KB5025305 in the month of April this year. This patch was bundled with other (security) fixes and patches in the recent mandatory Patch Tuesday update, so more end users are now affected by the problem. The April update is also said to cause read and write speed issues with SSDs.
In a comment to Bleeping Computer, Microsoft says it is aware of and investigating the problem. A fix for the problem is not yet available, but uninstalling -with all its consequences- would solve the problems.
Also read: Microsoft Patch Tuesday is light on fixes, but puts admins to work