ProTools now ignores all inputs, even midi, when other things respond

[GuitarSlinger]

Brand new setup on Mac:

Mac Studio
MBox Studio
Superior Drummer 3 (SD3)
Ventura (latest)

I'm still setting up over the past week, but...

PT and SD3 standalone both responded to midi drum set until today. Now, only the latter responds to midi (hits on drum set). For both, clicking on a drum with a mouse produces a sound.

Today I tried plugging in my guitar via an Aphex 207D preamp that is plugged via SPDIF into the MBox Studio. Also tried input 1 on MBox Studio front. PT ignores both. However, the MBox hardware reacts to both, as does the MBox Control software.

So basically, PT ignores all inputs while the MBox hardware and software react to both. I've rebooted everything several times. I've checked PT Setup/Hardware and Playback Engine, and I/O, restoring to default where able. I deleted the track with SD3 and recreated it and added the plugin. I unplugged and re-plugged things. No change.

It's dead, Jim. And I'm stumped. PT is now playback-only software. Would greatly appreciate any input. The only remaining steps are draining the other half of the wine bottle I'm going through and uninstalling/reinstalling ProTools, which I consider drastic.

Any ideas?