[NoGravitas]

I love Firefox Focus, but it's not suitable for your main mobile browser. What it is is a substitute for Chrome Custom Tabs.

Full Firefox on Android has a slow startup time if it's been pushed out of memory, which it usually is, because it's big. Firefox Focus is a way of quickly opening links from other apps without paying the cost of opening Firefox, while keeping an acceptable level of ad-blocking and privacy.

You should have both installed, set Focus as your default browser, but liberally use the "Open in Firefox" menu on Focus when you have real browsing to do.