You may have been a victim of the day.

It was flat calm in there for us last night.

There was some kinda music ashore and people dancing on the beach until about 5pm.
Then it got really quiet.

It was REALLY rolly in Flamenco Bay, Culebra the night before.
I suspect swells coming in from the remnants of Dorian.
It's open to the North.
I pointed this out as a possibility, but the crew was willing to deal with it.
It was not bad in a cat, but a monohull would have been miserable.