Affinity weird problems

 I love Affinity but these bugs or error are real embarrassing.

Exporting PNG resulted a weird huge blank document with small actual graphic on it. Look at this. The document size is just 968px x 747px at 144 DPI. 

But when exported to PNG from the right corner icon. The ridiculous huge blank PNG file is exported.

Luckily though, the exporting from menu Ctrl+Alt+Shift+W key still works well. It left me wondering, what is that problematic menu purpose then.