I've come across a reproducible hang when working with layers.
This happens with a new document and it happens with different source pictures.
EDIT: I went back and tried this on version affinity-photo-1.7.1.404.exe and the problem also happened there, but I don't remember it doing that in the past. I tried in on affinity-photo-1.6.5.135 and I straight up got an unhanded exception.
EDIT: Windows version 1909 18363.720, with latest cumulative Windows updates
Steps to repro:
Open a new document (this is the background)
Add another layer from clipboard
Select Layers (3a - Select Brightness/Contrast)
Click layer as if to drag layer
Results: The Affinity UI is now hung and you can't go anything, but kill the process in Task Manager. You can't open a menu, you can't even close a document with CTRL+F4.
Expected Results: At this point, I could drag the layer (5) to another location among the layers (e.g. down).
