I like to use VST
I choose many favorite styles in use
But when I open it again, these favorite styles disappear and can't be saved
Is this the problem of VST itself?

Hate to leave this appearing to be unaddressed. Best I can tell this was acknowledged to be a known bug in another thread.

https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=672878#Post672878