--"Mining long inserters and not getting anything back?"
By default, the mod setting "Simple long handed upgrade" is set to true, meaning that long inserters cost nothing besides the base inserter. Likewise, this also means that mining a long inserter will get you back its base form. This is to make it easier to convert between long and short inserters.
Setting this option to false should make the long inserter cost the usual amount of extra resources, and mining it will similarly return the long inserter to you.