Mac Pro headphone output not available

Mac Pro 3.5 GHz 8-core, 32GB RAM, Ventura 13.2.1

This computer recently started crashing at least once or twice per week; I've had it for quite a while now and this behavior is new. I'll guess it's result of a MacOS update. A few weeks ago, I wouldn't have thought that this is relevant, except today I made a connection.

I left my office for about 15 minutes and returned to notice that my Mac had restarted "due to a problem." Typical lately. This is also the first time in a few weeks that my headphone output has disappeared from the list of options for audio. I use that output to feed external speakers when editing, so it's a problem that this keeps disappearing. I don't like editing with headphones and the internal speaker on the Mac is even worse.

I'll tie its disappearance to the crash because I was in an edit session, using speakers plugged into the headphone port, before the crash. It's been several weeks if not a month or two since the last time my headphone option disappeared, and I've had other crashes in that time, but this time the headphone port was definitely available before / gone after the crash.

Is there any known cause for this? More importantly, any know solution?

TIA.

— Mike