I have upgraded my Kubuntu from 20.04 to 22.04. Firefox now is a snap app.
After the upgrade the Firefox entry is missing from KRunner. I can find it in the Application Launcher, if I click it Firefox starts as expected but the menu entry is missing the application icon.

I have noticed that after editing the entry in the Application Launcher, the application appears in the KRunner. But after reboot my change is undone and Firefox application is missing again.
This happens only with Firefox snap, other snap apps or flatpak apps aren't affected.
I have updated Firefox snap several times, the issue is still there.
Update
As suggested by Hannu, I have tried to
sudo snap remove firefox --purge
just to be sure also:
sudo rm -rf ~/snap/firefox
rm -rf ~/.mozilla/
and then fresh install
sudo snap install firefox
But it not solves the issue.
