In pots? They can't get enough water so the upturned plastic bottle trickle feed tricks can help.
I've had similar problems with my outdoor courgettes, it seems to start in the flower end so regularly checking that the flowers will pull off easily seems to help. The male flowers thing may be a red herring? It seems more likely to me that small slugs or insects are spreading bacteria when they nosh on the tender flowers that then gets into the cukes. If you just keep removing flowers when they come away easily & cutting out any spongey cukes you should get a satisfactory crop for the year though

My La Diva have been growing outside since May along with Tomatoes. All in BIG pots and watered twice daily. In this 30+ today maybe a third time and tomato feed regularly too.

This is an issue that has always corrected itself in the past & I inevitably end up with loads of cucumbers/pickles.

Have you tried fertilizing the female ones with a male flower?Easy to do and nothing to lose

did you grow them from seed or buy them as 'ready plants' if already growing I wonder if they were miss labelled as they if all female they shouldn't have male flowers. irregular watering is the main cause of fruit fail. it has been very hot lately so try increasing the humidity in the gh.

I grew from seed. I though I might cut back the side shoots and just see if the babies that are left grow and keep picking off male flowers. Tomatoes and peppers are growing well in same greenhouse. I will place a bucket of water next to the cucumbers to increase humidity.