I’ve had the same problem a couple of times, so consulted a local artisan cheese maker. His inputs were:
1) The culture is too aggressive. Either find a less aggressive culture, or back off on the amount. Too little and you just need more time. Too much and no way to recover.
2) I had been spraying the p. candidum on the cheeses. He said to simply add the culture to the milk and not spray. Trouble with spraying is that amounts and moisture are less controlled.
3) Temperature needs to be kept between 50 and 54 F.
So, on my most recent batch I added a small amount of p. candidum to the milk. Now, after 7 days I have a nice bloom of white mold. Plan to wrap all four rounds in cheese paper within a day or two. I will then age two rounds at 45 degrees in order to keep them longer, the other two at 54 degrees to eat sooner. So far, so good.