Sadly, Al, I clean everything before and after a make, with a combination of diluted bleach solution, immersing in a boiling vinegar solution and/or Star San, object dependent. I'm quite anal about it. I don't even handle my cheeses without food service gloves, changing them between cheeses.
I recently sanitized my cheese cave, too and the Caerphilly that's undergoing the same process the 'Berts did, hasn't even been inside the cave.
At this point, I'm hoping it's the culture. I used a litre of cultured buttermilk and left it out overnight to thrive. However, instead of ice cube traying in the morning, I didn't get it frozen until the next evening. Nearly a full 12 hours longer than normal. And in my haste, my thought is that I didn't clean the covered ice cube trays before filling them. For the life of me I can't recall if I did or not.
I've already got a Parm out (came out of the brine today) and I'm hoping its not gear related, or this guy might be done, too, only I don't know it yet. Obviously, it's got a different starter and I know I sanitized those trays before used them.
Here's hoping.