Willow cuttings suddenly losing leaves

Hi everyone! First time poster here; hope I’m
In the right place. Ive beet trying to grow willow cutting this year so I’m no expert.  I’ve several weeping willow and hybrid willow cuttings that have been doing well all summer but recently two of the cuttings have been losing leaves suddenly with no warning and where the little “branches” stem from the cutting have dark red/purple spots.

I’ve looked online and it’s saying it’s willow scab but it doesn’t completely look like photos I’ve seen. Anyone have any ideas? If it is willow scab are there any treatment measures/preventative measures I can take? I’d hate to see the cuttings die after the great year they’ve had.

P.S they’re in pots and I’m in USDA zone 6

I can't speak to the disease question. In my experience there are always a few willow cuttings that don't survive no matter how much love they get. So, I plant extra to make up for it.

Sometimes if there's a water issue, they will die back to the base and send out new shoots at ground level next year. So it may be worth it to wait before discarding.