So, the Jobo tank looks like this:
Your streaks look to be identically spaced to the support beams on top and bottom of the holder. The horizontal development line looks to be where the water level sat most often.
Looks to me like not enough liquid was used in the development phase causing uneven and streaky development.
I have no clue how that is processed, but as a pure guess
& because answers in comments are frowned upon
I'd be looking at "clip dribbles"
It looks like they were hung upside down from a bulldog clip to dry.
They're strangely evocative, btw - I fully expected to see horses in at least one, & maybe a guy in flat hat & baggy trousers with ...