Black dot error when using remote desktop connection

Question

This picture is a screen that uses Remote Desktop Connection.
When I logged on for work this morning, this phenomenon occurred.
Only the screens seen in Remote Desktop Connection are experiencing this problem, and other programs do not have this problem.
Rebooting the computer receiving the remote connection did not solve the problem.
Please help me.

I work at my home.
My home PC(Use for remote access) - Windows 10 : 21H1 (19043.1288)
My office PC(Windows 10 : 2004 (19041.1288)

• https://learn.microsoft.com/en-us/answers/questions/447912/remote-desktop-protocolor-connection-error.html

On June 23, 2021, I asked the same question because there was the same problem, and I proceeded with the method left by one person, but the problem was not solved.
For reference, at that time, it suddenly normalized a few hours later.

Answer 1

For folks out there that may encounter this issue. This is an issue with the RDP connection that is established from the host or client to the destination. Update your RDP connection and DISABLE Bitmapcachepersistenable.

https://learn.microsoft.com/en-us/windows-server/administration/performance-tuning/role/remote-desktop/session-hosts#client-experience-settings

When this setting is enabled, it creates a client-side cache of bitmaps that are rendered in the session. It provides a significant improvement on bandwidth usage, and it should always be enabled (unless there are other security considerations).