High latency when sharing screen.

[dimGo]

Good afternoon. In a computer lab of 7 computers + 1 teacher’s computer, the Veyon remote viewing and control program is installed.
Actually, what is the problem: when sharing the screen on 7 computers, there is a huge delay in updating the thumbnails (delay when changing the picture). Screen sharing takes a long time to start up.
What can be done about this?

OS on all computers: Windows 10 pro x64 license.
Connection via cable rj45.
Switch: D-Link des-1016d