Found this How do I make serial work on the Raspberry Pi3 (PiZeroW, Pi4 or later models)How do I make serial work on the Raspberry Pi3 (PiZeroW, Pi4 or later models)
I've had success with the same xBee modules on all other variants of raspis, seems like you just need to adjust the /dev/ttyAMA0 to /dev/serial0