No Access to new subfolder on network share

i use a NAS (Zyxel325) that contains all my movies and hosts a mysql database that is shared across 3 installs of Kodi (all on windows 10) and one install of OSMC on my raspberry pi 2.
Everythings worked perfectly until i reorganized the files on my library, splitting my tv folder into three folders. I rescraped my tv shows and all my windows based kodis can play them.
But the OSMC install can’t access the files that are in the new subfolder but has no problem to access the other subfolders in the same share.
smb:// - No problem to access old folder “movie”

smb:// - can’t access the content of the new subfolder “archive”

i already looked at the user settings for the share named video in the config of the nas and i have given the user “kodi” access to the folder.

What filesystem is the hdd in the nas?
Are there any permissions set that could prevent linux systems from reading them?

According to the Zyxel manual the file system is XFS / Ext4.
When it comes to the permissions i’m pretty clueless, so please bear with me.
the share “video” currently belongs to the admin account on the zyxel (just like any other share) and the users admin, kodi and osmc have full access rights. i’m really stumped because i can’t even adjust the access settings for individual subfolders within “video” so i’m kind of at a loss as to why OSMC has trouble accessing only some of the subfolders.

Would be good if you could post debug enabled logs that demonstrate the problem here so we can have a closer look.

Have a look here to see how to do that:

I now got a log (link below) but can’t get anything out of it.
I reset the user settings on the share back to what it was initially, marking the video share as belonging to “admin” and the share as “accessible to anyone” (the default setting in the nas config).