Double Firefox icons and can't uninstall Firefox after upgrading Ubuntu from 20.04 to 21.10

I upgraded my system from Ubuntu 20.04 to 21.10. After upgrading, I noticed I had 2 Firefox icons. So, I decided to reinstall it. I tried

sudo apt purge firefox && sudo apt autoremove

But, it only removed one icon. After that, I logged out and logged back in. But, It didn't help. Then, I tried,

sudo apt list --installed | grep firefox

and uninstalled all the packages. It still didn't work. So, I followed this question's answer, Removing Firefox in Ubuntu with all add-ons like it never existed. It didn't help either. Now, if I try,

firefox -v

I get the version of firefox & I can open firefox from Applications. But, if I try uninstalling firefox again, I get

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package 'firefox' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

How, do I uninstall Firefox? I'm asking this question from Google Chrome.

From your reply, I see you still have snap version of firefox. Try uninstalling it.

sudo snap remove firefox