· in the font tab,
· light master active,
· select (click on) a glyph.
· activate bold master.
· using Filters > Transformations,
· do something.
It will be applied to the light master, not the bold as it should. Looks like the change of active master is not applied properly.
(Re-)Selecting glyphs after the change of active master is a workaround.
This bug is new in Glyphs 2.