Watermelon production

[SheriDi]

I am trying to grow watermelon for the second time. Last year, the fruit got to about 1/2 expected size and shriveled up. I may have over-watering so this year I'll be monitoring that more closely.

My question is....last year and so far this year, it seems that there is only one fruit per vine. If one flower has been pollinated, no others will turn into fruit.

Is this normal?

Thanks in advance.