Remove function of Completed Download Handling not always working?

[Prodeje]

Sonarr version (exact version): 2.0.0.4753
Mono version (if Sonarr is not running on Windows): 5.0.0
OS: Synology DSM 6 Running Docker, latest images from linuxserver.io
((Debug logs)):
(Make sure debug logging is enabled in settings and post the full log to hastebin/pastebin/dropbox/google drive or something similar, do not post them directly here) https://pastebin.com/VeQMm5Zg full log EDIT: https://zerobin.net/?a1bbbcb18627ef66#2DHLYTjhY5/zVvcF4zvrD68FrOyJb0oLH7zQEl4PPWo=
Description of issue:
Intermittently Sonarr shows no progress in queue, NZBGet actually downloaded and shows Success. Remove function of Completed Download Handling not always working?
I hope this make sense by the title. Within Sonarr, I marked an entire season of a show as wanted. From the wanted tab, I selected the 8 shows and clicked the button to search selected. All 8 shows actually downloaded and even got placed correctly in their final destination. My issue appears to be in the communication of the cleanup between Sonarr and NZBGet? The other 6 shows were correctly tracked, cleared from NZBGet and no longer show in the Sonarr queue.
I am running a Synology DS916+ with docker using the latest versions. The issue seems intermittent, but happened yesterday on a similar request of a different show.
I only have the one download client and indexer. Within NZBGet download client, I have both items enabled for “Completed Download Handling” and “Failed Download Handling”. Add paused is currently off. I may need to understand what that does. Drone factory interval is 1.
At first glance it appears the Completed Download Handling isn’t working correctly for me?

EDIT: forgot to note, that S01E03 and S01E06 are the two episodes in this example that stayed in queue. The other 6 episodes processed out correctly. I couldnt fit whole log in free pastebin. I added zerobin with full log: https://zerobin.net/?a1bbbcb18627ef66#2DHLYTjhY5/zVvcF4zvrD68FrOyJb0oLH7zQEl4PPWo=

[markus101]

The remove will only happen if the import is successful, but the logs indicate the move failed; it looks like only a partial file was copied over and the rollback to correct that failed so subsequent imports are failing with the error: Destination already exists [/tv/The Blacklist Redemption/S01/The Blacklist- Redemption.S01E06.Hostages.mkv].

And the original error:

Failed to properly rollback the file move [/apps/nzbget/complete/tv/The.Blacklist.Redemption.S01E06.1080p.AMZN.WEBRip.DDP5.1.x264-ViSUM/_unpack/JswsPG0Seq8Eso.mkv] to [/tv/The Blacklist Redemption/S01/The Blacklist- Redemption.S01E06.Hostages.mkv], incomplete file may be left in target path. 17-6-9 22:48:33.4|Warn|ImportApprovedEpisodes|Couldn't import episode /apps/nzbget/complete/tv/The.Blacklist.Redemption.S01E06.1080p.AMZN.WEBRip.DDP5.1.x264-ViSUM/_unpack/JswsPG0Seq8Eso.mkv

[Prodeje]

what does that mean the root cause was? All of the other files were indeed matching groups except those two. All were 1080p except those two were 720p.
So those two original files failed and then it attempted to find replacements basically.

[markus101]

In those cases, it looks like something in mono failed: System.IO.DirectoryNotFoundException: Could not find a part of the path "", though I’m not exactly sure why it doesn’t log anything for the path and why the directory wasn’t there, especially if it left a partial file behind.

Generally Sonarr only does this check if he source and destination are on separate volumes, so if you can have Sonarr import on the same volume it should be less of an issue.