It's (shade) probably the culprit. I'd wait till february to transplant, and you might have to head it back if you don't get enough roots.

Pawpaw root systems are very fragile, especially the tap root.
If you aim to transplant them, you would have to ensure not to disturb the tap root.

I'd probably choose to get some seeds and go thru the process of growing a new one rather than risk losing them all due to root damage.

Its a tough species to uproot without killing.
Maybe others with more experience have better ideas.

I have a backhoe with a large bucket and the ground is very soft so I could probably get all of the taproot in one scoop.

It would be disturbed but probably/hopefully not too bad?

If they aren't ever going to produce, loosing them wouldn't be much of a loss.

I could thin out the trees that are shading them and sell the wood for saw timber or firewood, 40" diameter oak and hickory trees.

I transplanted a number of 5 - 7 year old pawpaw trees early this spring without taking monster root balls and all are doing well. Not to discourage taking as much root as you can - the more, the better - but it will still be okay with a smaller root ball. I would transplant just before bud break in the spring.

Very late winter or early spring transplanting is part of the secret. Pawpaw, unlike most deciduous trees, does not have recovery root growth while still dormant.

Thinning the top growth to balance for loss of roots is always a good idea, but strongly consider painting the truck and branches with thin white (or in any case light colored) diluted latex pain or whitewash (which will wear off in a year or two).

Full sun in 7b may be too much though. It is for mine.

Thanks to all, I will be transplanting next March or so!