KVM Switch issues

[CharlieGYW]

I have a work laptop (HP zbook) on Windows 10. Display 60Hz.
I connect/extend to my 34" curved monitor (HP M34d WQHD) via a USB-C>displayport cable, and all works well.

My own pc is a HP Pro Mini 400 G9 on Windows 11. Display 59.97Hz
This connects via an HDMI cable to the same monitor detailed above.

I want to be able to switch between the 2 computers easily without scrambling through cables, unplugging them back and forth.

So, I purchased a KVM switch.... a 'KCEVE AM-KVM201DP'
It features:
Input PC1; HDMI and USB connection (for my pc)
Input PC2: DisplayPort and USB (for work laptop)
Output: HDMI to the monitor
Plus peripheral USB's for mouse etc

My own PC appears to work perfectly with it.

The laptop however simply will not connect with the monitor.
The mouse, keyboard etc all switch over well, but the display will not.
I know its not the DP cable as I can connect that directly into the monitor and it works (once i've disconnected the PC)

Something isn't compatible from Laptop > DP cable > KVM > Monitor

I'm not too technically minded, so if anyone can please give me any advice, i'd be so grateful!
Have I simply purchased the wrong KVM switch?

[CharlieGYW]

I found some 'secret' buttons on the back of the monitor 😂
4 unmarked buttons plus a power one.
The 2nd one down was a simple source/input button.  2 clicks and it switches across!
No KVM needed, yay!