Didn't get Compiler skin

Completed Compiler a number of weeks ago, didn't post because there was a ton of similar posts at the time with vague 'looking in to it responses' and hoped it would be resolved at a later point.

I brought in the DNA, and a teammate with 6 vaults did all steps (I only have 5), and we started the fight. Had let a second team join us after we let them live. Seen other posts in here claiming the team that initiates the fight is "guaranteed to get the associated Codex unlocks" but the skin is earned from a Codex unlock, and I didn't earn either the skin or the codex unlock. I had previously completed the fight, with no additional teams or players, on a different character.