Frankfurt Catch-22: it takes an hour and a half or more to navigate the airport, but there's only enough space on the arrivals screens to show flights up to approx that much time in the future so you don't know where you need to go

Knowing which concourse is which helps, A is Schengen, Z is non-Schengen. I think D/E are also non-schengen? There are screens specific to concourses near branching spots which go much further into the future and are what you should double check