In distro Elementary OS 0.5. In to fact, UI UnityEditor have strange behaviour. Window have not stable size. All UI element may change their position or size.
I have a similar issue. When I try to scroll in the editor, the whole editor “scrolls” as it was a page, with the elements rendering on hover only. Actually I have it in less scale than in the screenshot, but it’s still annoying.
UPD: The editor window seems not to be moveable and resizable for me.
UPD2: I’m using Ubuntu 19.04