Re title. I must apologise for the title of this thread making it appear that this is XTOL's fault. Something like "Why are my developers failing?" would have been better.
Re bags of XTOL: I only bought one bag of XTOL, the one for 5L. That one bag consists of two packets, labelled A and B.
WHY is there fixer in your changing bag???
A good question.
I've been designing new developers, and discovered that an easy way to develop test-strips is:
(1) Fill three small graduates with developer, stop and fix.
(2) Put those graduates in a tray, slide it all into a changing bag, and dev-stop-fix inside the bag.
This system lets me dev a 1-2 frame strip of 35mm. This works well but isn't perfect. Fixer gets onto the clip holding the neg-strip (or my fingers), which in turn gets into the bag. Instead, I'm going to make a plastic holder to keep the strip flat, and drop that holder into an SS tank instead of using a reel. That way, I can dev a short strip in an SS tank with a minimum of chemistry. I run many tests, so it's a great help to be able to quickly dev short strips.
Like other posters, I thought that tiny amount of fixer-dust in the bag wouldn't hurt anything. And indeed this might not be the problem at all.
My next step is to load the film in a dark closet as Newt_on_Swings suggested. (BTW, I had a darkroom many years ago, but haven't built one in this house.)
If that fails, I'll mix a PQ developer as Rudeofus suggested.
If that fails, I'll ... switch to digital?
Mark Overton