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.