I realized my Sonarr instance was not getting RSS results at all. Having a very new error message:
An error occurred while processing feed. https://api.dognzb.cr/api?t=tvsearch&cat=5070&extended=1&apikey=<removed>&offset=0&limit=100: Document element did not appear. Line 1, position 1.
Checking the DogNZB website it appears their API is working but changed to following url:
https://dognzb.cr/rss.cfm?r=<apikey>&t=5070&num=100
Just to be sure: I know there were errors with the API. This issue is not related with any on these errors.
Thanks in advance