Hi Mr Uncle Charlie sir.....
I had the same with one of my colonies.
As soon as it got a bit colder and I added a heat source, invasion. Tried different foods, different hydration sources, cleaning the bin more often, nothing seemed to help. I never had too many of them, only had about 200 or so roaches, but it was enough to be irritating. Also had a really funky, musky odour. As soon as I put them in the sun, they- the @#$#@! goggas- disappeared again.
I have since changed over to a mix of pallid's and lobster's, and no problems.
You have to put a layer of vaseline as a barrier, but they have no smell, size from about 1 mm to about 40 mm and breed like crazy. I started with 100 about 3 months ago and probably have close to 500 or so.
Sad though, cause turks, imo, are the best feeders.
Good luck
Sent from my GT-N7100 a long time ago and far, far away.....