Background Update (without someone opening FF first) does not work

Hello! Currently we deploy Firefox via SCCM Package on our machines. The problem is, that Firefox currently only updates itself when you opened it once. This leads to all sorts of Vulnerability warnings etc. At the moment these regkey settings in HKLM\SOFTWARE\Policies\Mozilla\Firefox are configured: AppAutoUpdate (REG_DWORD) 0x00000001 (1) DisableAppUpdate (REG_DWORD) 0x00000000 (0) These two are enough for the updates, when the user opened Firefox (and created a profile). So we tried the information detailed on this page: https://firefox-source-docs.mozilla.org/toolkit/mozapps/update/docs/BackgroundUpdates.html To achieve a 100% unattended update we added following Key: BackgroundAppUpdate (REG_DWORD) 0x00000001 (1) which yielded no results. Firefox stayed on his old Version (V131 for this example). We also added pref("app.update.langpack.enabled", false) in the autoconfig.js File as kind of a 'hail mary' action (bc. the documentation wrote, that this setting should be disabled); but it still does not work. We've been through this rabbit hole quite some times now, and researching it also yields inconclusive results. (answers like: you still need to start Firefox once, before it can update). So, what are we missing/doing wrong? Is a true unattended Background Update even possible or is "start Firefox once to create a profile" still the only way to go? Thanks in advance for your time & help