It is probably stress. It is a greenhouse pickling cucumber. It does not need bees. and will be seedless unless some stray pollen is brought in. It was developed for growing under controlled conditions and may more subject to weather stress than a variety developed for open field growing. It seem many folks have problems with parthenocarpic cucumbers when grown outside a green house.
From Seminis which states "A very early pickling cucumber hybrid with outstanding total yield. This is a parthenocarpic variety that is not dependent on insect pollination. With adequate nutrition, forms 6-7 fruits at each node. Non-bitter fruits show very early and even maturing. The fruit length/thickness (diameter) ratio (L/D) is 3.25. Suitable for fresh market and processing. Resistant to Cladosporium and Powdery mildew, tolerant to Cucumber mosaic virus. Recommended for upstrings and bush culture in plastic film greenhouses and in the open field."
