The XBee3 most likely can't read the input that fast. If you are simply passing the raw input state change, the Xbee can only work at 1kHz https://www.digi.com/support/forum/78407/xpee3s-gpio-max-rate
If you are looking to read it in MicroPython I think you will get a "better" rate but I haven't found any documentation that will suggest the frequency the pin can be read at. Even then, you can't thread in MicroPython on the XBee so interrupts would be only possible in a callback.
Whilst the underneath EFR32MG can read the input fast enough I highly doubt Digi's XBee layer will present it to MicroPython quick enough.
Your best bet would be to externalise an MCU and send the data via SPI or UART.