Yikes, that seems like a pretty awful default for a content library - and no global setting to disable the behavior. It does look like most assets do have ‘Enable Gravity’ checked by default from UEFN.
Must take awhile before that kicks in during gameplay, so I haven’t been running into it immediately despite a really beefy machine. And they don’t disappear or /drop/ during gameplay - only during create mode? Weird behavior all around.
Even worse, the property is on the mesh components and not the class itself, so changing this requires going into each component one by one 