I am on the iPad version and just purchased a very large package 
First of all I love your software
- keep it up !
While the process of accessing the brushes is very slow (iPad pro 2018) it also seems to create issues.
For instance I have a case where another brush set seemed to get corrupted / I could see some of the Adamis brushes in the Frenden set.
I doubt I can share those brushes with you so perhaps could you ask the author to share them so you can test this ?
PS: I have asked them to break-down the package - awaiting answers.