Struggling with gyna lurida, what's going on???

[Jimbobtom]

I have attempted these I think 3 times now over the past several years. They always seem to dwindle down to 1 or 2 which live for a long time. This past attempt I thought I was going good, I had them in a deli cup and they matured from small nymphs to adults. I moved them to a larger bin and ended up getting nymphs. And BTW I put them in the exact same bin set up, temps, food, etc as my gyna caffrorum and gyna centurio. My caffrorum are doing well, they seem to go up and down in population, but still have decent numbers. My centurio are thriving to the point I've even somehow found an adult in my therea bin(still confused about that, all my bins have foam gaskets). 

 

So anyway. What's up with the lurida? I love their looks and really want to get a colony going. I'm back down to 1 nymph which has been living for a while now... looking and acting healthy. Why would the rest die off?

 

Could the bin be too large? It's a little longer than a shoebox with about the same height and width. Coco coir, leaf litter, rotten wood, sphagnum, charcoal. Ventilation on side and one top. Moist and dry sides. No CuC other than some small springtails. Im really at a loss to what's going on, would really appreciate some feedback!