Yep. It shifts every few weeks because new developments are happening. Don’t worry about fixing it. If one of you does not have a 9 to 5, that one should sleep when the baby sleeps (preferably the mom, since her hormones more likely shifted to allow intermittent sleep) and the other one should try to get their steady night of sleep to stay fresh and functional. The less suffering in the house from sleep deprivation the better. It’ll smooth. Best if everyone just knows to just roll with it.

Source: Midwife/RN with decades of experience.