I already had similar problem with preview panel:
- I just updated Glyphs to the new version (957).
- Added new master from previously exported instance (extrapolated bold).
Masters’ compatibility is OK everything seems fine (I have 3 masters: thin-regular-bold). - I created new instance: semibold.
(here appears my problem:)
I can see semibold instance in my preview panel, but It doesn’t update, when I changing shapes of the letters.