Second try, shorter and less confusing than before:

• DNSoverHttps interfering with my DNS block
• shown to be enabled in about:policies
• set to disabled in policies.json as well as in about:settings.

The picture shows a console window witch the respective policies.json key being set to false (disabled), while the about:policies firefox page in the background shows DoT to be enabled.

Version is 140.1.0esr on Artix (Arch). Anyone can confirm?

Edit: It’s not a broken profile; same happens in a fresh one.