it might be a female.no longer than 2 months ago i bought a pair of G.iporagensis.they spawned about 3 weeks ago.I had exactly same situation.they spawned and 2 days after i found dead male
female is very agressive,trying to attack anyone passing near tank.Like yourself i have a group of healthy youngsters with her.
that's weird that both of us had similar situation.
i hope they will be looking like the male you lost.