KVM and M4 Mac Mini - working...kinda

I just replaced my M2 Mini with an M4 Mini. The M2 worked great with my TESmart 4 port KVM switch. The video and keyboard work perfectly with the M4, but the mouse doesn't. I tried with the USB and HDMI cables that I used with the M2 and have tried 2 other USB cables, but the mouse isn't recognized.

I've connected a USB mouse directly to the M4, which enables me to use it, but I'd really like to get the 'M' part of 'KVM' working instead. Does anyone have any ideas/suggestions? Thanks!