Thank you hrst for your interest in the issue. I will this weekend try to expose some rolls/sheets and be very careful in the processing the first roll in my old chemistry. If everything works Ok I will assume that my earlier treatment was defect, particularly I think my last washing method was too agressive. If i get the same problem, though being very careful, I will mix a new liter C-41 and see If that will solve the problem, in that case it seems reasonable to assume, I think, something is wrong with the old chemistry.
BTW, in view of my earlier experience of C-41 with agitation quite similar to ordinary B/W development in an ordinary Paterson Tank, and one try with the Jobo machine using the low rotation speed -without any problems! - I felt that the faster speed, especially for development of 8-10 minutes at 30°C, was a kind of exaggerated type of agitation. On the other hand I read the latest Jobo CPE machine (Jobo CPE +) deleted the slower speed as not needed. Well, I don't know. But perhaps you are quite right that modern color emulsion is so robust that what I managed to achieve (!) is very peculiar. I will make a new try and at least go on with the fats speed. I will keep you informed of the results.
PS. I scanned with my Epson 4870 several of these ugly looking negatives and several of them was very good without any retouch!! DS