Hmm, both Paul Robeson and Black Russian are mid
season producers for me and they are both productive.
It is possible to have a dud as seedling for sure...

Does it have the exact same growing conditions as the other plants? Is it being shaded by the others? Did you plant it initially in a peat pot? Sometimes the roots don't grow out of those and end up growing around and around in the pot. Mine is a robust plant and just setting fruit now, but then I planted out late.

Hi, I am haveing the same issue, mine were grown from seeds, I have used the same bed every year, over the winter I till in good compost and horse manure (aged and chemical free) I had a horrible deer attack, the other plants had all been 5 ft and thriving lots of fruit, deer took them all down to about 14 inches, except the Russians, which were and still are about that high. Not in a peat pot. I planted them all at the same time, and even the ones in a different bed are the same. Could it be the seeds were too old? They were a gift and I did not look at the date.