Bug: Appalling image quality on export w/o copied character image

Hey community,

I really don't know how to make the subject any better without making it MASSIVELY longer than it already is I'll try to be as brief and concise as possible describing the bug (?) I encounter.

I'm designing a quiz. I customized the master slides to include a cut off character which appears on every slide which bases on said master. Now I came across a very peculiar thing:

1. When previewing and/or publishing the project as is, I get appalling picture quality, see the no_image.story file as well as the screenshot attached.
    
2. When I copy the character from the master slide and insert it on ANY slide in the project, it can even be set to hidden (!!), the quality is perfectly ok on previews and exports for any slide, check image.story and respective screenshot..
   

 This has nothing to do with export settings, the quality is appalling on default, on 40% as well as 100%. As soon as I delete the copied-from-master-slide character from the slide I inserted it into, the quality goes to super-bad, if I re-insert it, quality goes to perfectly well.

For your reference, I inserted the trimmed down .story-files as well as screenshots. On the "image.story" check the intro slide's timeline, there is the character which I copied from the master slide as a hidden object.

Anybody shed some light onto this issue?