Tromboncino squash - possibly a question for mum

I know mum (and others) grow these regularly so am hoping someone maybe able to help. I've grown tromboncino for the first time this year and have been pretty impressed - my courgettes were useless this year so extra pleased that they performed. I grew them up trellising but found that many (probably most) of the fruits started to rot at the end long before they grew to any real size with, somewhat surprisingly, those that were on the floor on escaped vines being less affected! I tried both leaving the flowers in place and pulling them off once the fruit had set with no apparent difference.

Does anyone know if this is this a common problem, or is there a solution to prevent it happening?

It's not a common problem, I think probably to do with the weather we had this year, because some of mine did the same thing. It may have been a bad year for pollinating insects, lack of good pollination can cause the flower ends to start rotting.

Perhaps it will be worth trying to pollinate them by hand next year.
look here for hand pollination tips

You can add some Dolomitic lime to the soil to boost the calcium levels, then.