When I use the connection below, it works fine.

source--->VE883T--->VM7584--->VM3200--->VM8824--->display

But when I change the connection and connect VE883R to VM8584 like below, the switching time will become 10 seconds to get the display.

source--->VM7824--->VM3200--->VM8584--->VE883R--->display

Is there any setting to make the switching time shorter?

It's because of the compatibility with VE883.

After upgrading the VE883 firmware to v1.3.125, problem solves.