Could Track N° be defined on 1 digit only ?

[Facel]

Hello

I have initially tagged and organised my music files with jriver.
Most of them are FLAC, (very very few MP3 or Wav)

I have recently installed MinimServer on my Synology and discovered that my clean Jriver Tags was not as clean as they should be with MinimServer

When I use Jriver or some Iphone apps to access MinimServer Library I have quite many Albums (files) ending with a question mark ...as well as the artist name and the song name tags.

I have noticed that if I change the track number from a 1 digit to a 2 digit number (example 2 => 02) I have no questions marks !

Does MinimServer requires to have at least 2 digits for the track numbers ?
Is there a way for processing automatically a large amount of files ?
=> for changing from 1 to 2 digit the track N° tags
=> for feeding the AlbumArtist tag (which is left blank by Jriver)