PACKED Data Manager processes data in real-time. If your Blend file has a lot of data, under some Scope mode and Data Type configurations, the add-on may have to process a lot of data, which may result in Blender viewport becoming sluggish. Collapsing the panel, or hiding the sidebar by pressing N , will disable data processing and make PACKED Data Manager inactive. This way, the addon is active only when it is visible and when you are ready to interact with it.
Why objects, meshes, materials, etc. do not show in their names which collection, object, or mesh respectively they belong to?
Some data types, such as the ones described, can be shared by more than one other data type. E.g.: a mesh object can be a linked duplicate which means that all such objects would share a single mesh. In such cases, it is unclear which parent name should be displayed.
To see orphan data, you have to use the Global scope mode and if the Data Type you have selected has any parent Data Types, make sure that none of the parent Data Types are toggled-on.
I have more than one Armature item enabled in the list but the Bone list in Edit mode shows Bones of only one Armature.
In Edit mode, the Bone list shows Edit Bones. These Edit Bones exist only in Edit mode. If you have only one Armature Object selected in the 3D viewport when you enter Edit mode, only Bones from that one Armature will be displayed.
To display Edit Bones from all Armatures, make sure to select all Armature Objects in the 3D viewport before entering Edit mode.