If it does that every year on all three plants I would suggest getting rid of those and buying some new plants. Looks like a fungus or disease to me. If its a fungus its obvioulsy spread to all the blueberry bushes. Just start new this year with some 2 year old plants from a distributor and you will right back in it come next spring.

What did you use for potting mix in those containers?
And how deep is the growing media?

Doesn't look like any disease. Rather, drought stress. Now you get to figure out why.

In any event, my opinion is rather than replant these, you'd be better off starting anew with fresh plants come spring. Once damaged, blueberries seldom recover enough to do well again.