Batwoman Brasil already posted a comparison picture:

https://twitter.com/BatwomanBR/status/1429924069827358732
....they seemingly changed the wig a little as it has less "volume" now in season 3, and it seems that the hair is now a little longer.
Will have to see if other shots will confirm that, but I'm pretty sure this change is no accident.
Well, I do prefer the new(er) look as the wig is less dominant....which is a good thing for me.