As I recall, if you paid more carbon tax you got more back. That is not, I think, how UBI is supposed to work (e.g., those paying more taxes don't get a higher UBI).

Everyone gets back the same amount. You can't even know how much carbon tax you paid, because it's levied at the source. It's a redistribution scheme at the expense of polluters.

I really hope you recall incorrectly, because that indeed makes 0 sense except as the result of a farcical political system.

If you received a refund in the same ballpark as you were taxed there would be no point to it right?