I have this same issue on an M2 Max Studio running Ventura 13.6. I have an apple keyboard and trackpad connected via lightning<->USB-A to a KVM, and then via USB-A to the Mac Studio. The trackpad will move the mouse pointer around, but dies as soon as you click the keypad. I then moved the KVM output to a USB-A<->USB-C adapter, and plugged it into the USB-C port on the Mac studio, and it mostly works okay now, but the connection will lock up intermittently and I have to unplug the connection to the Mac studio, and plug it back in again. This typically happens after returning from screen saver, but I've had it happen before under normal active operation.
I had this exact same connection set up previously with a Mac Mini (2014) and it never gave me these sorts of issues with the I/O ports.
skyshock21
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution