Microsoft's September 2026 Patch Tuesday update has introduced several technical problems for users of Windows 11. Reports indicate that after installing the latest security updates, issues have arisen with features such as Remote Desktop, Hyper-V, USB audio, and Always On VPN. Microsoft has confirmed a specific bug related to Always On VPN, a tool used by businesses to connect employees' devices securely to their internal networks. According to BleepingComputer, affected systems may experience endless connection loops or complete failures when attempting to connect to the corporate network. This issue does not appear to affect public VPN services like CyberGhost, Proton VPN, or Surfshark. The problem is affecting Windows 11 versions 24H2, 25H2, and 26H1 after installing updates KB5124008 and KB5124012. It occurs when the Always On VPN profile allows Windows to automatically select a connection protocol, such as IKEv2 or SSTP. If the initial connection attempt fails, the system attempts to switch protocols, which can result in the connection getting stuck on "Connecting," restarting repeatedly, or failing with the message "The specified port is already in use." This can prevent users from accessing internal company resources if the Always On VPN is a key part of their network access. Microsoft has not yet provided details on the technical cause of the issue. In the meantime, administrators are advised to manually select a specific protocol, such as IKEv2 or SSTP, instead of allowing automatic selection to bypass the bug. This problem is the latest in a series of issues linked to the KB5124008 update, which was deployed on September 8. Since then, the update has been associated with problems like Remote Desktop Services failures, the disappearance of shared folders in Hyper-V-based Linux virtual machines, and malfunctions with USB Audio Class 1.0 devices. Microsoft has released out-of-band updates on September 14 to address some of these issues, and an optional update, KB5124010, has been deployed to continue resolving problems on Windows 11 24H2 and 25H2. This update fixes issues like disruptions to File History backups, but problems with USB audio devices and trust relationships with Active Directory domains are still under investigation. As Microsoft continues to address these challenges, users and administrators are advised to monitor updates and apply fixes as they become available.