In 12.2 and 12.3.2, "Add to Favorites" was an option from the "My Catalog" perspective. In 12.3.3 and 12.3.4, this option no longer exists.
Release : 12.3.3, 12.3.4
Component : AUTOMATION ENGINE, AWI
Caused by a defect
This is a bug that has been fixed in release 12.3.5
A possible workaround for this is - if the user has read permissions to the object:
Right-click the object in "My Catalog" and choose "Open"
On the top menu bar, choose "More" and then "Add to Favorites"