Not recommended, it rarely resolves an issue, but here:

factory reset

I’ll second this comment. Factory Reset rarely resolves any fundamental issues, but it might accidentally work around an issue -- for a short while.

Why do you think that PORT needs to be Factory Reset?

If you want to sell a unit, purchase a used unit, or install in another system, then Factory Reset is a good plan.

Thanks. My unit doesn’t need to be reset. Just wanted to know how, since there are no buttons on the front like my Connect.

Must do a factory reset (on a Port in my case) in order to downgrade from S2 to S1.  A turntable is connected to the Port but needs to work with speakers connected to ZP100 (and will only work in S1).

factory reset, as I posted earlier.