I think your efforts are commendable! Firstly, mold isn't necessarily a cob issue, it's a straw issue. Most certainly well established within the bales-or at the very least-inoculated, prior to use. Mold can grow amazingly fast especially during the drying process if temperature is in its favor, and it's common to see a bounty of sprouts emerging from damp, moldy bales, even overnight.
The straw looks a hefty amount and I'd agree on the suggestion of a little Borax. Not sure how that would play out on the already-built wall though. Perhaps a garden pressure pump sprayer, but certainly allow breezy airflow into the area. Ideally about 84-86F for 8 hrs will halt mold growth. But it's now Nov. If you've still got walls to get up, relocate and burn any open bales or nearby wet straw and start anew. I would suggest based on your photos to reduce the amount of straw and keep your material ratios consistent.
Also, it appears you've got cob on the ground? I'm not sure what you could do about it at this point; what's done is done. I would however set out your eves aggressively at 3-4ft. Lastly, again if you still have walls to go up, consider using branches proper for wattle, unless poultry wire is all you have. It couldn't be more contrary to earth building, its failure rate being high in most applications.
Best of luck moving foreward!
