When you use “set as default” to an object into the Catalog Editor this one doesn't appear as default into the placement tool view, the system always remembers the latest item used. How to resolve this?
Default catalog only applies when you have no "Most Recently Used" (MRU) in the user preferences. In order to see default, you will have to delete your current user preferences from this location: “C:\Users\User_Name\AppData\Local\Bentley\OpenBuildings Designer and then restart your OBD.
The feature is only intended to define what you see the first time you use a tool, not every time you use the tool. Once you start using the tool, the tools will show the last-used catalog item instead.