Taxes (Installation) "Whoops, something went wrong"

I am trying to set up a self-hosted (Ubuntu 21.10, Apache2, php 8) server.

All is well until I try to add a new tax rate.

The URL is localhost/1/wizard/taxes.

I can press "Add New" and enter in a row for a tax rate, but when I press "save" it just goes "Whoops" and returns me to the Taxes screen.

I cannot skips this afaics, when pressing "next" it just flips me back to the same URL.

Nothing in the logs afaics

Guessing it might be a database or other permission, but I don't know what.

Strangest thing.

I came back at this today, and the darn thing "just worked."

No clue as to what I screwed up.

Anyhow, whistling a happy tune etc