Booklets Not Showing Now

[Budgie]

It could be my fault or a changes to apps but what used to work using BubbleDS Next on Samsung S6 and playing from Minimserver with a booklet pdf in the directory of the album no longer works for me even after I have found the button on the new and greatly revised version of BubbleDS Next.

I have followed the the Minimserver instructions and checked for illegal characters but file name is correct and as I mentioned it all used to work.

I have noticed one issue which may be relevant. If I select the Booklet and a pdf file is present I get a note after the naming convention notice
<album title>.pdf which states:-

The booklet for this album would be located at : /storage/emulated/0/Documents/BubbleDS/booklets/Fiocco_ Petits motets Volume 1.pdf. (Note missing underscores and hyphen)

It appears that the file name has been corrupted because what I have in my data is :-
/Fiocco_-_Petits_Motets_Volume_1_(Scherzi_Musicali).pdf

I am posting here but am not sure where problem rests.

Can those more knowledgeable please enlighten me?