Both packs consist of a lot of similar but different items
1’st pack
Every single file is approved
2’nd pack
Aaproved only one (1’st) file. Others are rejected.
What reason could be of approvement or reject like that?
I think the reject was because of their similarity. It’s not allowed to upload separately close similar SFX without “significant differencies” (as reviewers say). Such ones considered as “variations” should be included in one item’s uploadage, and be priced as single item, As you see from the price of the second pack, not all of them was determined as separated sounds (hard to say which ones exactly though 
).
that is strange, because both packs are not priced as single sounds
And both pacs have very similar sounds. But as i mentioned above.
First is fully approved and only one file approved from second.
All i want is just make a possibility for buyer to choose what to buy a whole pack orr just one sound from this pack. But envato as i understand prefer not to give the buyer that choice.
IMO it would be the best option to make a possibility to sell packs separetely, if buyer just want to have only one element from pack. By separately i mean an option to upload not only 1 archive for pack, but also separate archives fo single sounds.
See: Ticking pack contains 10 sounds and is priced $5, so all of sounds are considered as different enough by reviewer. That’s how price of pack is being formed: the summa of single items prices’ halves, 1/2s.
But the microglitches pack contains 12 files and is priced $4, 4x2=8, 12-8=4 files left the price, it means they were counted as variations (which are forbidden to be uploaded separately). Surely there is the option to upload pack’s content as a singles, but only enough different ones. Not sure why only one of them was approved. Perhaps the reviewers found not much sense to offer another ones separately because of their similarity, as they are already presented in a pack to choose between $1 and $4.
Or there is some point of misunderstanding.