It looks like Gummy stem blight but... there are many strains of GS blight with varying symptoms and to make identification harder different cultivars of the same vegetable can display different foliar symptoms. Tebuconazole- and Chlorothalonil-based fungicides both work against GS blight and a host of other fungar diseases so you may want to try that.
For two years do not grow any cucurbits where those squashes are growing now, destroy all material when you pull up the plant at the end of the growing season and to err on the safe side buy you squash seeds/seedlings from a reputable source. GS blight can be both seed- and soil-borne.
One final note: do not use neem oil unless you have pests you want to get rid of and even then use it sparingly and apply it around sunset. I have been driven nuts by trying to diagnose foliar damage to several plants which ended up being spray damage caused by excessive use of neem oil.
I know it's marketed very shrewdly but it's still a pesticide (albeit one with questionable effectiveness) and should be used carefully.
