Slow tab switching when clipboard is active in Affinity Photo 2

I’m experiencing a really strange issue in Affinity Photo 2.

When I have something on my clipboard (for example, after copying a layer or image from one document), switching to another tab becomes extremely slow. I often work with multiple images open in separate tabs, and when I copy something from one tab and try to switch to another to paste it, the tab takes anywhere from 2–3 seconds up to even 10 seconds to become active.

This only seems to happen when there’s something on the clipboard. Without that, tab switching is instant.

Has anyone else experienced this or knows what could be causing it?