Cucurbita moschata the species to which Butternuts belong have some white coloration on the leaves which often follows the veins and can be neat along the viens or blotchy.
Neem oil can also leave white residue on the leaves most likely where it follows the veins to drain off the leaf, so this...
This is a huge problem, usually with bigger companies but small ones are not exempt.
Currently I am having the same issue with beans, I'm finding one particular bean sold as 5 different beans that don't even have the same seed coat color or pattern.
Ecuador is right next to Peru, chances are the day light sensitive ones much like Nuna would like a 12hr day and 12hr night and cool temperatures due to elevation.
If they do flower please take note of the day length if you could please.
This is kind of ironic, last night before bed I was actually looking at that bean on the association Kokopelli site and thought it might be an interesting horticultural type.
I'm guessing being a French cultivar would likely cause it to struggle with heat and drought, how are the pods holding up...
That is quite high actually and does explain the cool tolerance and also reminds me of Peru and the Nuna which despite proximity to the Equator hate heat due to their elevation being so high.
Journey get yourself a good seed source for Amish Paste then save your own seeds when you find a good one. I've had it grow through blazing hot summers and even had self sown plants surviving frosts and fruiting in an open field during winter. It makes a good sandwich tomato and a good paste...