got the engram for tek boot but no element

I have actually recently (last month) did a boss fight with Broodmother. Summoned the Broodmother, popped into the arena, and proceeded to ate her face with our Mega Rexes. However, at the end of the fight, when we were all checking her inventory, 3 other got spawned outside of the arena, with our Rexes intact at the summon point, and they all had to spawn at a bed. I, on the other hand, got stuck inside the arena, no broodlings, no broodmother, no other spoil other than the trophy and a flag. NO elements. No engram.