I had something like this when I was not filtering our hard water full of city chlorine. I put in a darkroom inline filter and haven't had any problems since. I wasn't sure it was the water as I was using Arista film. It's like one of the cheapest films you can get.
I thought it was either, crappy water, chemicals, air bubbles..
I think for me, it turned out to be chlorine in the water reacting with the chemicals. I use rodinal pretty much all of the time, so I can't comment on any other developer. I can't prove that but I installed the house filter on the cold water side in the darkroom and I had no more problems. I dumped all my chemicals and started over with the filtered water.
Greg