You followed my thinking. If you figure out it is just the one let me know please, in the mean time I am going to try and rinse a few with a garden hose to see if I can replicate the issue.
I think it's just the one but I haven't taken a journal so I'm not sure. I usually use a hose on soaker or the kitchen sink on soaker. I read that thread about an older model that did this and what the housing looked like and that doesn't look like any of my cases. Also I don't get any current in Lake Travis and I'm rarely moving fast.
The DUROC is on my BP2 which is on an AL40 side slung. I'm not opposed to the possibility that maybe every in once in awhile I do something stupid like drag it in the silt or fold it over with the garden hose. Hence why I've gotten into the habit of a predive vacuum test on all my 2nds before each dive.