When I run in the directory where firefox(Ver. 52.5) is located, I get this
andy@7_~/Downloads$ firefox -v Mozilla Firefox 65.0.1
I do have 2 versions, but it should be reporting Ver. 52.5?
If you are running simply
firefox from the command line, then you are actually running the 'default' Firefox installation, likely installed and updated by your package manager. You can verify with
which firefox. You'll probably get
/usr/bin/firefox which is a link for
/usr/lib/firefox/firefox.sh. If you have indeed another installation of Firefox, you need to call the executable for this other version. You can do this by doing something similar to
./relative/path/to/this/other/firefox.sh, or simply going to the folder of this executable and
Alternatively, you can add this other version to your
$PATH, but you'll likely want to name it differently than simply
Firefox to avoid conflicts.