I have used some vector brushes in illustrato (see highlights). When file saved as a pdf the brushes no longer correctly represent what's in the file, they seem to lose a lot of their transparency. I sell the mentioned brushes on exchange (HighlightsandShadows Brushes) as well so I would like this fixed. Both viewing the pdf file and opening in ai show the wrong results.
This problem has occurred since upgrading both mac os and illustrator to latest

However if i open the ai file in shop it looks as it should.