Switch off automatic copying of L to R in Master Pages

I’d like to have different text tokens in the headers of my L and R pages, but, for some reason, Dorico is now automatically copying L page to R and R to L in the Master Pages. Is there a way to switch this automatic copying off.

Delete the relevant frame on one page. Then add a new frame in the same position.
I believe that should fix it.

Thanks, Leo. That did do it, tho I’d like to know what caused it.

The frames on the two pages are linked. This is intentional behaviour - for most master pages, most people want exactly the same thing regardless of whether the page is verso or recto (right or left). If you delete one of the frames and recreate it, Dorico doesn’t see it as a mirror of the other page, it sees it as an entirely separate frame.