This is because the creator hasn't marked the morphs for "preload".
If you know which morphs are not listed, you can change the settings at the Package Manager:
Go to the Package Manager and search for the VAR that includes those morphs. Click "UserPrefs" and selekt the "preload morphs" option. This will load the morphs at VaM start, not only when opening the scene or look.
Though, you have to know which morphs you are missing and where to find those morphs.