Hello and thank you very much.
Unfortunately I can’t verify this on a different theme, because the “promo-popup” is a function of the Woodmart theme, which is not present in the other themes.
The promo-popup contains the close button “X”: I didn’t insert this button, but this is a part of theme settings (I send a screenshot). This “X” button, I believe, does not allow other popup close buttons to work.