Probably just a fluke. I've been ordering from them for many years and never had a problem.

I am looking at the Dixondale Farms website and trying to figure out what form they sell the onions in. It looks like they basically sell bunches of green onions. Is that correct? Do those travel and plant well?

They do indeed sell onion sets and these sets do indeed travel and plant well.

Yes I have been getting their products for years now. I look forward to an order and get them in about two days. Makes fall gardening fun. They come in bunches of 60 and about 6" to 8" long in a box in which the mailman complains about the smell. WHAAAA.
Just get the ones for your area. Need to get 3 bunches or more to be worthwhile. Remember if you do get them ¾ inch deep and 4" apart. I have had major climate changes in which maybe one third bolted which means you got to use them first.

I just planted mine on Thanksgiving weekend. I ordered one bunch of the Sampler Pack from Dixondale. When all was said and done I had 110 onions in the ground. BTW Dixondale sells onion transplants rather than sets. Yes they travel well, plant well and grow well.