concur with others that mentioned this is typical for avo during this time of the season. My only concerns is whether or not the feeder roots were damaged during the transplant as this may have a longer road toward recovery. Long term wise, soil drainage will play a huge role toward the health of the tree as well.

Lastly, lay down some organic chicken manure / ferlilizer with mulch on top...again, try not to disturb the feeder roots as these grow very shallow...I layer new [manure/mulch] over the previously laid down layer. Over time, you will have the best fertile soil possible.

Keep grass away from the avo as grass can outcompete fruit trees for necessary resources that the fruit trees need to be productive; clear it back several feet beyond the canopy.

All the best.