I've recently started developing my own colour film with the Tetenal C-41 kit. After scanning with my Epson V600 I've noticed that some of my frames have these blocky marks on them (see a few that I've circled in red below).
I've developed two rolls so far, one at 30°C and this one at 38°C, but some frames from both rolls have these blemishes on them.
Are these simply small water spots, or some kind of problem in my developing or scanning process?