If your water quality is good .
Its not weird , its pretty normal from my experience . It seems to take longer for a pbass to get used to the new environment at 4" than it does at 2-2.5" .... took a few days with the smaller 2-2.5 " bass Ive started with , but 2 weeks or more for the Pbass I started with at 4+" ... I think the longer a pbass is living in one environment .. the longer it takes for him to get used to another .. if that makes since?
not saying this is always the case , but that has been my experience which is pretty limited.
Id check my water , and just give him more time .