Thumbnail bug when having a child actor in a blueprint [4.8.3]

As soon as I created a blueprint with child actors (to composite a desk with drawers you could open), it started interferring with all the blueprint thumbnails across my project.
As you can see below, the various drawers (the blue and cream ones) and doors are overlayed onto every thumbnail for a BP in the entire project, making them useless.

Hi turfster,

This is a known issue and has been reported into our system as UE-17453. In the future, please report bugs to the bug reports section of the answerhub so we can better assist you. Thank you!