Zucchini/ronde fruit petering out long before flowering, sighhh

Not sure why I keep having this problem in recent years.

Teeny tiny fruit appear, but they're pale and sickly and stop growing -- this is long before the flower opens, so it's not a lack of pollination.

So far only one nice-looking fruit has made it to flower-opening (the air conditioner zucchini) -- and sadly it was before there were any males around.

Since then, others on that plant, and on other plants, not looking promising.  I'm removing the fruit that clearly look like duds, so that the plants can focus on other things.