see: https://affinity.help/photo/English.lproj/index.html?page=pages/Selections/selections_transform.html?title=Moving and transforming pixel selections
https://affinity.help/photo/English.lproj/index.html?page=pages/Selections/editSelectionAsLayer.html?title=Quick Mask selections
To transform a selection (leaving pixel unaffected):
Do one of the following:
Press Q.
On the Toolbar, click Toggle Quick Mask.
From the Select menu, select Edit Selection As Layer.
Select the Move Tool.
Resize, reposition, rotate or shear the selection on the page using the displayed handles or, for precision, use the settings on the Transform panel.
Any move operation on the selection crashes photo 1.8.3.641
100% reproducable on a new document.
testq.afphoto
