Update Yesterday I've contacted Ilford and today they answered, From looking at your images and the info you’ve provided, I can confirm your findings do unfortunately link to a statement we put on our website 02/03/20 – I’ve attached a link to it below in case its helpful. There isn’t anything I can see to indicate your processing is triggering the issue. But given the issue has unfortunately affected 2 different products / batches, I can only best guess that one of the triggers is the films have perhaps been subjected to heat. Not in your ownership of them – but perhaps whilst in transit or at the distributor / dealer / shop. Your film serial numbers correlated to the below batches :- Delta 100 - 4507 - 59DTA1C02-2 (manufactured Nov 17). HP5 plus – 4524 – 67BHN1C01-2. (manufactured July 18). They will send me new rolls and I will test my process to clear all doubts. Thanks to everyone. Later I will make an update.