Oh! Sun PLUS wind!
Sun plus wind PLUS recently transplanted.
That sounds like a challenge for any root system, let alone a new one. Maybe in this case a little wilting is not so much a sign of a PROBLEM as an indication that your healthy plant is doing as well as can be expected when sun and dry wind blow water away from the leaves faster than roots can take it up.
My guess is that it will bring itself into balance after the frequent drenchings are over and you get some months of less rain and drier soil.
Just keep an eyeball peeled for the first few weeks when there's no rain, but the sun and wind are still there. You might have to jump in with some supplemental water or even shade or misting, if the roots are still "lazy" or not very deep when all the surface water drains away or evaporates.
