Thank you, Mark!

Since the solutions are all freshly mixed for each run, I can't think of a reason how the first developer could have been contamination by the fixer, or get consistently contaminated. I have tried about 10 runs now. AFAIK, the reason behind the contamination causing the blue tint is that the fixer acts as a catalyst, thereby over accelerating the effects of the first developer. So, I'm wondering if slowing down the activity of the first developer by adding the starter solution will help. In Kodak's documentation, it did list as the lack of starter solutions as a possible cause of blue tints.

I have also reduced the concentration of Part B by as much as 10% to see if it makes any difference, and amazingly it didn't. I have also added the equivalent of 4ml per litre of 5N NaOH, and again, it didn't lift the tint by too much visually. This is pretty frustrating. I'm going to try raising the amount of NaOH even more. I don't have a densitometer, and I think it's a good idea to get one just to be methodical about the analysis.

This whole process is so robustly consistent that it seems nothing I do changes anything. I'm going to try adding salt, soya sauce and ketchup, and i bet the result is still going to come out the same!

Getting the Fujifilm controls is a good idea, but it's pretty hard to find. The usual online stores don't seem to stock it. Even the Kodak control strips are hard to come by these days. So far, only Kull and Company has it listed. I'm going to ping them and see how it goes.

Thanks for the reply!