Csrss.exe has a deadlock with Microsoft Excel or Microsoft Visio
The issue occurs because of a problem in the Win32k.sys driver.
If a remote desktop session exits before the session is completely initialized, the state change notification of the session is not sent to the third-party driver. In this situation, the driver can leak resources, such as a system thread, in the context of Csrss.exe because the third-party driver cannot unload. The leaked thread causes the remote desktop session not to exit completely. After the computer is running in this status for some time, the Local Session Manager (Lsm.exe) blocks new incoming connections. Additionally, these orphaned sessions also cause the shutdown process to stop responding. Therefore, you experience the issue that is described in the “Symptoms” section.
Configure session idle and disconnect policy in studio or MS policy for the VDI. That is logoff the session after disconnect for sometime