I recently noticed that Glyphs now translates line breaks in the (edit) text as huge gaps, especially if I am working at a UPM smaller than 1000. If I convert the font to 1000 UPM then gap gets smaller. Is it independent of the UPM? I think it should rather be em-related. Ideally, for my taste, they should simply be exactly word spaces.
Another strange behaviour I noticed is that when I select an instance for the preview bar and then toggle between the masters (for editing) then the preview jumps up and down, and sometimes changes its size as well. If I select an instance then I’d expect the preview to be independent of the selected master.