Custom Details Panel does not save asset on reloading editor

As of recently, I began doing a fair amount of detail panel customization. Having a pointer to the object being customized, I can set its member variables in accordance to what the details panel does. In my case, I am modifying a C statically allocated array.

 TAssetPtr<USoundCue> SoundCues[SomeSize]

Modifying the asset, saving the changes, and opening it again retains my changes. Restarting the editor does not. First question I’d like to get out of the way before posting some code is: **Is details customization only intended to work with UPROPERTIES ?

EDIT: **I wrapped my array with a UPROPERTY() macro and that did not achieve anything yet.
EDIT: After trying a TArray UPROPERTY with no success, I am beginning to think the only way the details customization works is via the use of IPropertyHandles. Any confirmation on this and whether there are other ways?