I started using PMK pyro about a year ago. My TMX negatives don't stain nearly as well as my tri-x negatives. I am so impressed with the pyro negatives that I use it as my main developer over 90% of the time. Only when I need compensating development, or high speed do I use anything else.(posted 8266 days ago)I don't know if you are using tap water, but Gordin Hutchings "Book of Pyro" notes that pyro is very sensitive to impurities in the water. This is especially important for roll film processing.
I have used distilled water to mix all the chemicals involved, and use six water baths, 5 minutes each for the rinse. Filtered water should be fine too.
It's a pain, but my water supply is high in sulfur and minerals, and I have not yet installed a filter. You might try this and see if it solves the problem.
As far as fixer. I use the Kodak rapid fix, I just leave out the hardener. I'm sure TF-4 is just fine too.