Episode upgrade loop

Sonarr version (exact version): 4.0.8.1874
Mono version (if Sonarr is not running on Windows):
OS: Docker
Debug logs: Sonarr Debug Log - Pastebin - Textbin
Description of issue:

Sonarr is continuously upgrading certain titles even though upgrades are disabled for all quality profiles.

The logs show that the upgrade is happening due to an improved custom format score.

2024-08-19 12:58:12.1|Debug|UpgradeSpecification|New item's custom formats [] (0) improve on [] (0), accepting

An example of this in the logs can be found by searching for Evil.S01E13.1080P.BluRay.x264-BORDURE.mkv.

What setting controls this behavior, other than Quality Profiles > Edit Quality Profile > Upgrades Allowed?

I had a similar problem due to a preferred string profile I was using. The resolved issue is here…

Check it out, it may give you some ideas.