Indexer timeout / Failed to read complete http response

Sonarr version: 3.0.6.1342
OS Win: Server 2019
Debug logs: https://pastebin.com/vZJRqQm0
Description of issue:
There seems to be an issue with the HTTPClient.
I’m getting timeouts to some serivces constantly.
There are no issues if i use IE11 Edge or Firefox on the same machine.

Example

2022-01-03 15:52:32.6|Error|RefreshSeriesService|Couldn't refresh info for [401915][The Faraway Paladin]



[v3.0.6.1342] System.Net.WebException: Failed to read complete http response ---> System.Net.WebException: Timeout für den Vorgang wurde überschritten.
   bei System.Net.GZipWrapperStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   bei NzbDrone.Common.Extensions.StreamExtensions.ToBytes(Stream input) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Extensions\StreamExtensions.cs:Zeile 13.
   bei NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:Zeile 132.
   --- Ende der internen Ausnahmestapelüberwachung ---
   bei NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:Zeile 150.
   bei NzbDrone.Common.Http.HttpClient.ExecuteRequest(HttpRequest request, CookieContainer cookieContainer) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\HttpClient.cs:Zeile 126.
   bei NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\HttpClient.cs:Zeile 59.
   bei NzbDrone.Common.Http.HttpClient.Get[T](HttpRequest request) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\HttpClient.cs:Zeile 286.
   bei NzbDrone.Core.MetadataSource.SkyHook.SkyHookProxy.GetSeriesInfo(Int32 tvdbSeriesId) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\MetadataSource\SkyHook\SkyHookProxy.cs:Zeile 50.
   bei NzbDrone.Core.Tv.RefreshSeriesService.RefreshSeriesInfo(Int32 seriesId) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\Tv\RefreshSeriesService.cs:Zeile 63.
   bei NzbDrone.Core.Tv.RefreshSeriesService.Execute(RefreshSeriesCommand message) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\Tv\RefreshSeriesService.cs:Zeile 227.

This is not a sonarr issue

Timeouts and other networking issues are a local issue or ISP issue

I have to disagree.
If i test the indexer nyaa.si i get this as a return message:

2022-01-03 18:30:53.3|Warn|Nyaa|Unable to connect to indexer

[v3.0.6.1342] System.Net.WebException: Failed to read complete http response ---> System.Net.WebException: Timeout für den Vorgang wurde überschritten.
   bei System.Net.GZipWrapperStream.Read(Byte[] buffer, Int32 offset, Int32 size)
   bei NzbDrone.Common.Extensions.StreamExtensions.ToBytes(Stream input) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Extensions\StreamExtensions.cs:Zeile 13.
   bei NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:Zeile 132.
   --- Ende der internen Ausnahmestapelüberwachung ---
   bei NzbDrone.Common.Http.Dispatchers.ManagedHttpDispatcher.GetResponse(HttpRequest request, CookieContainer cookies) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\Dispatchers\ManagedHttpDispatcher.cs:Zeile 150.
   bei NzbDrone.Common.Http.HttpClient.ExecuteRequest(HttpRequest request, CookieContainer cookieContainer) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\HttpClient.cs:Zeile 126.
   bei NzbDrone.Common.Http.HttpClient.Execute(HttpRequest request) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Common\Http\HttpClient.cs:Zeile 59.
   bei NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchIndexerResponse(IndexerRequest request) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:Zeile 322.
   bei NzbDrone.Core.Indexers.HttpIndexerBase`1.FetchPage(IndexerRequest request, IParseIndexerResponse parser) in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:Zeile 298.
   bei NzbDrone.Core.Indexers.HttpIndexerBase`1.TestConnection() in M:\BuildAgent\work\63739567f01dbcc2\src\NzbDrone.Core\Indexers\HttpIndexerBase.cs:Zeile 343.

2022-01-03 18:30:53.3|Warn|SonarrErrorPipeline|Invalid request Validation failed: 
 -- : Unable to connect to indexer, check the log for more details
2022-01-03 18:30:53.3|Debug|Api|[POST] /api/v3/indexer/test: 400.BadRequest (300779 ms)

400 bad request is a client side error.
I can open https://nyaa.si fine on every browser on the same device so how can this be a networking issue ?
Only possible solution would be that some settings on the sonar http client are wrong that are fine on all other browsers ?

Again timeouts are not a sonarr issue

That’s the response from Sonarr’s backend to the UI, it returns a 400 response and some details on the error.

In this case Sonarr’s backend didn’t receive a response from Nyaa before timing out.