It is highly because the Asynchronous loading on assets. Content browser are highly associated with the usage of TSoftObjectPtr/TAssetPtr. This should include all Blueprint assets.
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Those type only try to load when you are “about” to use it, for example :
- Opening it in editor
- Using it on run time.
- Relevant to the startup log mentioned "Lazily Load … "
You can possible force load it, by setting stuffs in project settings. It kinda bothers me as well for certain asset wouldn’t show up if I never opened them within a session.
and from what I’ve know, it wouldn’t have impact on run time.