Unwanted double bar before time signature change

Hi. This may have been answered but I have been unable to find it online. I entered a time signature, say 4/4 and changed the preceding barline to a double bar. Now, any time I change the time signature to 4/4, Dorico inserts a double barline before the change. It doesn’t do this with any other time signature. How can I stop this?

I have figured out something: if I add the time signature with the popover or from the general pool of time signatures, this won’t happen. It only happens when I select it from “Used in this flow.” It’s too hard to keep track of which time signatures make a double bar and which don’t.

I think this is the clue! Using the popover is simplest.