@realnerf Correct, we regularly change our backstories, which dictate what players spawn with at character creation. We have not deleted older PTR characters for a few months now, to provide some level of persistence. Because of that, players could end up with different gear setups – such as the case you pointed out where you have a GS 600 item (from prior mutators testing).
Additionally, no matter the backstory, we try to provide a small level of variance/randomness as well; the same backstory box could grant you a slightly better or worse item. But if you continue to use a character created from the GS 600 backstory, your unopened boxes should still grant similar items.