Sportage drives fine in 2wd.
It drives fine in 4wd straight or gradual turns.
When the sportage is in 4wd it can Not make sharp right or left turns or Uturns
The wheels seem to lock up

Anyone have any ideas?

NOrmal and must be avoided totally. Thus truck must NEVER NEVER NEVER be operated on hard surface in 4WD. This is a "part time 4WD", with a solid link (no differential) between the front and rear driving shafts so it cannot compensate for different wheel speed between front and rear when in turning . It will eventually bust the hubs, or the front differential, or the transfer case.