So, I checked again, the total loot from Artifact Lockboxes so far, just want to understand the system (I play on Darth Malgus and Star Forge servers both):
DM server:
Slinger/Sniper toons got only hands from Artifact Lockbox (Upper Body) (5 pieces), or only relics from Artifact Lockbox (Lower Body) (2 pieces);
Senti/Mara toons got only implants from Artifact Lockbox (Upper Body) (5 pieces), or only boots from Artifact Lockbox (Lower Body) (3 pieces)
Sage/Sorc toons got only cuffs from Artifact Lockbox (Upper Body) (3 pieces, started those toons later);
SF server:
Senti toon got only chests from Artifact Lockbox (Upper Body) (4 pieces), or only relics from Artifact Lockbox (Lower Body) (3 pieces); it has 1 258 implant though but it came from Lockbox which was obtained not from Ossus weekly but from a Command Crate (they seems similar, may be a coincidence);
Slinger toon on SF server is the most lucky - it has 5 different 258 items obtained from Ossus weeklies, and there were only 3 same items in 8 weeks;
[disclaimer: now I must say to all advisers do not worry - I farm crystals every week too and every of those toons has 20-25 crystals as well, and about 200k of UCs in legacy banks collected in last several months, I could have "4 BiS 258 sets on my account" too like some cocky kid was bragging before, I just don't want to create 8 toons of each class and to brainlessly grind the crystals - all I want is just to play for my own fun]
So, all this is very suspicious, and it's not look like as a random; I would agree if 1-2 toons had similar items per weeks, but not all. That is why I suspected that this is either a bug or the developers have made an algorythm of this "rng" that makes ppl to spend more time for gearing. And I heard from several ppl on those servers that they had similar problems. And I tried to google and seen some ppl on reddit complaining that they had 3-4 similar items in a row. And even in this topic with very few inhabitants someone said that he had only implants/relics so far, and the other one who "had 1 character get 3 chestpieces in 3 consecutive weeks. I've had others that get 3 Accuracy implants in 3 straight weeks".
And now I'd like to ask you again - do you really think that this is a real RNG? And is there anyone else who had similar problems?
P.S.Sorry for my English, it's not my native language tbh, but I speak 3 other languages better than English.