Unknown JPG files being downloaded

Sonarr version (exact version): 3.0.10.1567
OS: Debian
Description of issue: I noticed that last night Sonarr downloaded an image for a bunch of shows and called it unknown.jpg.

Looking at the logs it is downloading the clearlogo from TVDB. It seems that this is not the correct behaviour? I would assume that the clearlogo should remain in png format (it is in this format on TVDB) and should be named clearlogo.png (or similar)?

I am also not sure what the ‘Path doesn’t exist!’ error means, but the file was still created.

Example below:

2023-05-22 01:40:12.5|Info|RefreshSeriesService|Updating Prehistoric Planet (2022)
2023-05-22 01:40:12.8|Info|RefreshEpisodeService|Starting episode info refresh for: [418505][Prehistoric Planet (2022)]
2023-05-22 01:40:12.8|Info|RefreshEpisodeService|Finished episode refresh for series: [418505][Prehistoric Planet (2022)].
2023-05-22 01:40:12.8|Info|DiskScanService|Scanning Prehistoric Planet (2022)
2023-05-22 01:40:12.9|Info|DiskScanService|Completed scanning disk for Prehistoric Planet (2022)
2023-05-22 01:40:12.9|Info|ExistingMetadataImporter|Found 0 existing metadata files
2023-05-22 01:40:12.9|Info|ExistingSubtitleImporter|Found 0 existing subtitle files
2023-05-22 01:40:13.0|Info|ExistingOtherExtraImporter|Found 0 existing other extra files
2023-05-22 01:40:13.0|Info|ExistingExtraFileService|Found 15 possible extra files, imported 14 files.
2023-05-22 01:40:13.0|Error|MetadataService|Couldn't download image /config/MediaCover/990/unknown.jpg for [418505][Prehistoric Planet (2022)]. Path doesn't exist!

[v3.0.10.1567] System.InvalidOperationException: Path doesn't exist!
  at Mono.Unix.UnixFileSystemInfo.AssertValid () [0x0000f] in <e3eec4d51bc747d29a47738c484239ee>:0 
  at Mono.Unix.UnixFileSystemInfo.get_IsSymbolicLink () [0x00000] in <e3eec4d51bc747d29a47738c484239ee>:0 
  at NzbDrone.Mono.Disk.DiskProvider.CopyFileInternal (System.String source, System.String destination, System.Boolean overwrite) [0x00007] in C:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Mono\Disk\DiskProvider.cs:231 
  at NzbDrone.Common.Disk.DiskProviderBase.CopyFile (System.String source, System.String destination, System.Boolean overwrite) [0x000ba] in C:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Disk\DiskProviderBase.cs:231 
  at NzbDrone.Core.Extras.Metadata.MetadataService.DownloadImage (NzbDrone.Core.Tv.Series series, NzbDrone.Core.Extras.Metadata.Files.ImageFileResult image) [0x00038] in C:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\Extras\Metadata\MetadataService.cs:455 

2023-05-22 01:40:13.1|Info|RefreshSeriesService|Updating QI
2023-05-22 01:40:13.1|Info|MediaCoverService|Downloading Unknown for [418505][Prehistoric Planet (2022)] https://artworks.thetvdb.com/banners/v4/series/418505/clearlogo/628e63b95a75a.png

The clear logo was added to Skyhook, but Sonarr isn’t aware of it. Sonarr v4 will eventually have support for it, but at the moment they will be treated as unknown (and incorrectly downloaded as jpgs).