Gary, what is the Angle value of the rectangle that you are dropping the image onto?
I have only ever done this for a dropping onto a clipped photo, a straight box doesn't detect the image and it appear over the box.

I assume you are talking about Xara Designer Pro+ 23.3.0.67471 SL x64 Aug 17 2023, today's update?
@Xara, thank you for the update as I have just finished a client site, suffering the multi-second delay if the Web properties dialog was open. All speedy again.

Acorn