Try all of the above!
Often several different small adjustments will do the trick, but sometimes you have to go with the flow a bit and let the wood go where it wants.
This is a prime reason for leaving tips wide early in the process.
Is the bow back to brace height yet?
I normally say let the bow just rest on the tiller, but maybe in this case try clampnig it and that may help you see if it's limb or handle related.
Make small changes and don't necessarilly try to correct it all at once, do a bit, work it some more and it may settle down as it draws further.
Del