With the version 130, Mozilla introduces a new navigation bar in Firefox for Android. If you don't like it, you can disable it in the "Secret Settings".
I was not a fan when it popped out on my screen. But, after sometime, it's pretty useful and saves a tap on the three dots button.
Got used to the new bar quickly, however, I absolutely dislike that they hide parts of the URL/domain.
Didn't find any related config in about:config or secret settings.
With this in place, I'm probably going to continue using the old navigation bar.