Just sent it to Rainer already. Maybe wait until he had a look to avoid unnecessary work.
The support address reaches us both. I will board a flight in a minute, so Georg is likely to respond earlier.
I had a look at the file and it seems that there is a problem with more than one bracket layer group. I try to fix it. But in this case, the first set () is almost identical to the default layer so you can safely remove it.
Edit: I fixed it
I just installed the latest version and there is no difference 8-I
There hasn't yet been a new beta version since @GeorgSeifert fixed the issue. The next version after Glyphs 2.4.2 (1032) beta would include the fix. fyi.
I would be good (if not crucial) to include this information on anchors and components (in)compatibility in the built-in Show Master Compatibility tool.
That’s the version I have.