Horizontal Spacing of Rests Under Beams

I started notating a piece in 6/8, and I found what strikes me as an odd engraving quirk.

The rhythm I'm working with is eighth-note, eighth-rest, eighth-note, then it repeats—and the stems are all pointing down. When I put this rhythm into MuseScore, the placement of everything looks great, except that I'd like to add a beam over each rest. No worries, I can do this quite easily, but then the rests slide to the left (either that, or the second note slides to the right), and the spacing looks off. This is only an issue when the stems are going down; when the stems point up, everything looks great again.

I'm pretty sure this isn't an issue with any presets I have, that it's simply an engraving issue. I've attached the file so you can play with it yourself—or tell me what I'm doing wrong.