Mac mini: MIDI inputs not recognized, monitor ghosting

Sequoia 15.7.2

mac mini with Intel I7 processor, 512 gb ssd, 32 gb ram.

I have ghost images on monitor screen when closing programs. This computer is set up with a music program,

Midi inputs for control, and an audio interface.

The program is not finding the midi inputs, and check with midimonitor indicates that the computer USB inputs are not being found as well. All USB ports seem to be ok with keyboard and mouse.

Where can I check to enable these? Using a different computer indicates that midi monitor is working. This is also a dedicated system, meaning that once it is working, it will not be connected to the internet or anything other than the midi and audio.

Thanks

Thom.