When you say doing a complete circle, is it tilting its head back to the point of spinning uncontrollably on the floor then looking stressed and disoriented after the spinning has stopped? (Could this be the bird version of epilepsy?)
There are Youtube videos of birds with this distressing condition.
https://www.google.com.au/search?q=yout ... stargazing
This symptom has several views among birdkeepers, some seem to think in can be cured with mediation, others say put the bird out of its misery.
If the bird you have is just moving around the cage in a deliberate, compulsive way from perch to floor it could be the same as when a large animal has been kept in a small cage for a long time, they take to pacing and rocking.
I would give it a little time to adjust and maybe even put another bird or two in with it once quarantine has passed just to see if the other birds can distract this poor thing enough to stop the compulsive behaviour.
Good luck and I would love to hear what happens.