Deer got into my garden twice this year and ate the tops of my potatoes so they never flowered. The plants keep growing back and look healthy but there doesn't seem to be any potatoes. I may have over fertilized too by using the pine shavings from the chicken coop. Wondering if it's the chicken manure or the deer eating the tops.
It is likely a combination of both.
The deer eating the flowers and leaves may have caused growing and pollination problems.
The fresh manure may have burned the plants or had to much Nitrogen which causes lots of leaf growth and little potato production.
Here are some links with more information.