Firefox is driving me crazy by "upgrading" 'http' URLs to 'https'

Hi there. Since quite a while Firefox is trying to enhance our browsing security by "upgrading" connections from "http" to "https." This may generally be a good idea, but it is literally driving me crazy at the moment because it also does so for "internal" sites I host within my LAN (such as my "Home Assistant" instance or a Zigbee coordinator, accessible via its own hostname and web UI). However, these connections will fail, because I don't have certificates for my internal hosts, and thus there is no "https" listener. :-( (I use my own subdomain "<host>.city.internal.example.org" internally, so Firefox may be confused?) I feel this behavior has become "more aggressive" within the last few days, so maybe it is due to a Firefox update? Is there a bullet-proof way to prevent Firefox from doing so? I've already set the below options to false: - dom.security.https_first - dom.security.https_first_for_custom_ports - dom.security.https_first_for_local_addresses - dom.security.https_first_for_unknown_suffixes - dom.security.https_first_pbm - dom.security.https_first_schemeless - dom.security.https_only_mode - dom.security.https_only_mode.upgrade_local - dom.security.https_only_mode_pbm Help, please! I'm close to abandoning Firefox in favor of a different browser, because at the moment it's close to being unusable for me anymore... :-( Kind regards, Ralf