I work with many many systems, multiple accounts, so I add setup syncing on new browser fairly often. The problem is that whenever I add a new one, it resets the settings on all of the synced browsers. It's always the same settings that get reset, and they're not reset to any value I would've chosen, therefore I know there's not a lingering browser with different settings that's screwing up the rest. However, to make sure: I eliminated everything from my account, set up a few browsers, and manually copied their profiles over. Restarted them a few times. Double, triple-checked that their settings are identical. Next I installed a new browser and before setting sync on it, I changed its settings to match the other's. I added it to sync, and again all browsers reverted their settings including the newly '''configured ''pre-configured'' browser.''' It's infuriating. Among the usual changes are re-enabling/checking of: * Enable picture-in-picture video controls * Recommend extensions as you browse * Recommend features as you browse * Show search suggestions in address bar results * Ask to save logins and password for websites These are other settings I'm not completely sure if they're modified or not, but only because they're locked down from modification through policy management systems such as Profile Manager (Apple devices) or Active Directory (Windows, Windows Server): * Settings under Firefox Home Content * Homepage URL * New tabs setting * New requests for Notification, Location and all other permissions and update checking are disabled too. * Block pop-up windows — Sidenote: it's 2023, this is more of a nuisance than helpful. Sites don't spam popups anymore, not reputable ones at least. One last thing I've noticed, is that when these things are reset, presumably because they "synced down" from some master profile responsible for the preferences you didn't set. So if that was the case, in theory you should be able to change them back and "sync them up" back to that profile, right? But when you correct one of these change, that correction isn't replicated to other browsers in the group yet other settings like themes, extensions reliably do. It seems purposeful. I saw in '''about:config''' entries with "prefs" and "sync" on them, but I haven't found any documentation about them. Are any of these useful to keep the browser from resetting itself?