Those who are facing problems with the snapd revert command can manually download snapd=2.68.5. The steps are below:
snap download snapd --revision=24724
sudo snap ack snapd_24724.assert
sudo snap install snapd_24724.snap
I had a fresh installation of Jetpack 6.2.1 and performed an apt update and upgrade. After that, I installed snapd 2.68.5, and now Firefox is working fine. Refrain from apt upgrade unless the fix is pushed.