Bubble marks in c41 tetenal

Hi, I'm getting white spots and bubble marks in some of my negs using c41 tetenal. They're not noticable on the negs with a standard scan from Epson 750 but when I darken the scan(levels) then they are visible.

This is the 3rd time setting for Tetenal using 4 min and a 15 min fix as per booklet times. I do notice that after the blix stage it is frothy at the end of the process but not when pouring the solutions in the tank. I am using a jobo for processing. My wash is usually 4 mins after blix. I give std 1 min stab with no agitation at the end.

Anyone experience this and can suggest what is wrong and how to prevent?

Thanks

The BLIX works to completion, and I don't think that it matters if it bubbles, as long as you agitate properly. Are you 100% sure that these artifacts are in your emulsion and not just drying marks? If you reuse your STAB too many times (and the 15 minutes BLIX time indicate you did reuse that kit several times), impurities will build up which can cause these.

Can you *see* the bubbles after it's (supposedly) dried? (there was a url link here which no longer exists) (Maybe). I could see if I looked quite hard. The solution in that thread didn't work. I had to buy some film cleaner and wipe it down once after it dried, which added another 20 minutes or so to drying. It was quite annoying.... enough to make me not want to process C41.