Can not switch back after a while but can swith back immediately

[XiaoXiLe2023]

Hi,

My monitor is PHL 271S7Q, macbook is air m1 and PC system is win10.
I use "m1ddc display 1 set input 15"(operation A) to convert the monitor to the PC and use "m1ddc display 1 set input 17"(operation B) to convert the monitor to the macbook.
When I do operation A and do operation B immediately, the monitor converted from the macbook to the PC then from the PC to macbook successfully.
However, when I do operation A, wait for 5 seconds (or longer) then do operation B, the monitor converted from the macbook to the PC then stayed at the PC, couldn't swith back to macbook through operation B.

Do you have any idea what may account for this phenomenon?

THX