Fissure relic bug - relic openned, no loot awarded

[F3lbunny]

I had started a fissure mission on IO.  I clicked to back out of the group as the countdown began since I forgot to mod my weapon but it put me into the mission anyway after flashing a relic select screen at me for a split second.
I finished the first five waves and collected 10 reactant to open it, got the reactant buff and everything but as the mission finished It did not let me select a prime part, despite consuming my relic.
As luck would have it, there was a Necros prime blueprint up for grabs which I missed out on.