As a former manager I felt like the first 90 days, even as long as the first 6 months, after onboarding a new employee was spent trying to figure out what motivates them, how to communicate with them effectively. One of the hardest parts of manager is managing someone who likes their praise/criticism presented in a drastically different way than you.

Most managers I've had in the past don't make the effort or make a pretty small effort to adjust based on the individual. I've spent a lot of time managing up in the past to mitigate this.