Duplicates and issues with favorites in the dock

Since upgrading to 21.10, I've been having two issues in the dock.

1. Sometimes, the system won't let me add certain apps to favorites. The option does not appear when right clicking the icon. This seems to be random, though. Meaning, in another session, I might be able to do it.
2. Some apps in favorites duplicate in the dock when I open them. The new icon appear below favorites.

Have any of you experienced this?