Continuing the discussion from Mini 4 (Mac) Mouse issues:
After continuing to be frustrated with the issues in being able to control my Macbook Pro, I decided to try another KVM device I have, which is the Sipheed NanoKVM.
I made all of the physical connections, including HDMI and a USB-C to USB-C (which PiShop support claims to be problematic) and it just works… perfectly. No tweaking or changes needed to the Nano. Even the Nano mouse jiggler functionality to keep the Macbook awake is flawless.
Needless to say, this reveals that this is squarely a PiKVM issue and incredibly frustrating that a device that sells for about $50 has no issues whatsoever and my $200 PiKVM Mini still is not working correctly…
Those other devices also don’t typically have an OTG port attached to a Raspberry Pi that is the heart of the piKVM. The v4 model is using the CM4 which has a separate power so the PiKVM doesn’t lose connectivity in bios or through a restart, but since the device supports PD but not through the OTG port, devices (especially Apple targets) get confused and try to send it power through the OTG port, but the PiKVM rejects it but also doesn’t properly negotiate data because of the target trying to send power instead.
The solution is to not use a USB-C to USB-C cable but an adapter with the USB-A to USB-C cable into the OTG port. Then the target doesn’t try to negotiate power. If it still doesn’t work, try the kvmd-otgconf utility and dynamic USB functionality to disable the MSD and reboot the MacBook with the device plugged in, there is more automatic trust established vs a freshly plugged device, but also check the accessory trusy setting in the macOS settings and allow the devices there.