I originally bumped into this w/ 8.0 and just reconfirmed it is still present in today’s nightly (b2019050902).
Here’s how to reproduce it:
- Start a new project using the “Perspective Menu Nav” template
- Open the “Header/Header” view
- Add any new component to the root flex container. It appears on the far right by default
- Select the new component and try to drag it left
- Observe that it will move before the “Spacer End” component but then get stuck unable to move past the “Options” item
- If you adjust the “display” property on the “Options” component so it is visible, then you can now move the new component past it
Probably a low priority since there is a workaround, but still annoying.