Sonarr permission issue - unable to determine if files is a sample

[skiwlkr]

Sonarr version (exact version): 20190320-15
Mono version (if Sonarr is not running on Windows): 5.18.0.240-12
OS: synology
Debug logs: https://pastebin.com/ebHNjEvR
Description of issue: unable to determine if files is a sample

Hey there, maybe somebody can help me out.
I got an issue with permission rights with sonarr and nzbget on a synology.
When I download something with nzbget and the download is done its in the dst folder. From that sonarr should rename it and move it over to my media folder but somehow it’s not happening.
If I log in via ssh and change the permissions of the file to sc-nzbdrone with “sudo chown -R sc-nzbdrone /volume1/…” Sonarr recongnizes the file instantly and is doing the renaming and moving. Everytime I download a new file in the file is stated the the owner is nzbget.

What I already tried:
chown -R on source folder
chmod 777 -R on source folder as root
checked that sc-nzbdrone is in same group as nzbget -> sc-download
giving read/write permissions to group sc-download
reinstalled sonarr

I already found a thread on the sonarr forum about it.

New sc-download setup can't access files even with full permissions

You are asking that in the wrong forum. The devs have nothing to do with the synocommunity. They kinda screwed the pooch for upgrades when they altered the user nzbdrone instead of just adding that user to the sc-download group like they did with deluge. Sometime the best thing to do is to start “fresh”. For instance, instead of trying to tweak folders packages and myself fiddling in the *nix layer have been messing with in the past, I just created a new shared folder for my download clients…

So far I couldn’t get it running. I’m running out of ideas.
thanks for the help