Background blur is not calculated automatically when moved because it sounds in a group.
Could you add a bit more information about your issue? It'll be nice if you find it possible to list the steps to reproduce your issue and share a video or document with us.
Thank you for the report! Now it's absolutely clear.
We'll fix this issue in one of the future releases.
I make a square and then I add it to a group, if I move it on an image like a wallpaper, the background blur is not calculate.