Problems printing onto Oriental Seagull FB VC

I have a batch of Oriental Seagull Variable Contrast Fibre which has been opened for a couple of years. Some sheets show darker streaks in the darker areas, almost as if the print had been developed to a point and then developer poured over in streaks which has further developed these areas. This effect does not occur on a batch of Fibre Warmtone VC which I got from the same source but has been open for less time.

I am using Tetanal Variospeed (a warm tone developer) mixed as recommended at 20 degrees Celcius, with Ilford Ilfostop, and Ilford Rapid Fixer. I had developed other sheets of Ilford RC paper prior to this but I'm certain All chemicals were within recommended capacities. I have noticed this effect before on this batch of paper.

Additionally a couple of white finger prints showed on both prints I made.

My darkroom technique is not the most scrupulous and I am assuming the fingerprints are mine from handling the previous print before it was fully washed after fixing. However I've not had either of these effects with any other paper.

Is the problem with me or the paper? The streaking does not happen with all sheets from this box. Should I develop for longer? Use very fresh developer? be much more scrupulous? Go digital?

Thanks

I had some similar anomalies with Seagull VC paper that was left open for a number of years. The problems I had were white streaks and sometimes dark splotches that would appear during fixing, although the paper appeared somewhat muddy as well.