Sorry to ask this, as I know its already been asked and I did check the archives. But I need to confirm my guess.
I have tried processing 8x10 JandC 100 in Pyrocat HD with Glycol. I recieved the developer already as a pre mixed liquid (Formulary Kit). And I am processing the film in a Jobo 3005 Expert tank on a roller base.
Both times, the film has come out extremely thin, almost completely clear except for the highlights; which seemed pretty normal on some of the negatives. The shadow detail was non existant. I processed an exact identical set of Negatives in my usual D76 1:1 and they came out fine, so my guess is either the developer has gone bad, or has somehow gotten contaminated.
My process run in the jobo is a 5 minute pre-soak, 14 minutes in the developer, 30s water stop, followed by 5 to 6 minutes fixing in fresh Ilford Hypam.
Any ideas or advice is greatly appreciated.