Outline mayhem in brevecomb.case when exporting with latest Beta

When I export with the latest Beta, this happens to my brevecomb.case character.

Left working Glyphs file, right exported OTF. Maybe you can spot the difference.

Background: point placement by myself, foreground: point placement by Glyphs export.

brevecomb is perfectly fine by the way.

Is that on me? Did I do something wrong? If so, what exactly?
It exports perfectly fine with a prior stable version.

Can you send me the .glyphs file?

File send.