Xbee Series 2 doesn't wake up

Hi, here is my problem,

I use Xbee series 2 (XB24CZPIS004) and I have set up a basic communication between two Xbees (one connected to Arduino and the other to the PC). Everything works perfectly until the moment I put Xbee to sleep, or better until the moment I try to wake up the Xbee from sleep mode.

I use the pin sleep mode, by setting ATSM1 and Arduino successfully puts to sleep the Xbee by setting an output digital pin to HIGH which is connected to SLEEP_RQ. But when I set this digital pin back to LOW the Xbee doesn’t wake up and the weird thing is that when I measure the voltage on that pin (Pin 9 in Xbee) is still HIGH, while the digital pin from arduino is LOW(I measured it by disconnecting it from Xbee). But wait it gets even weirder… while it’s sleeping I pulled its pin to GND with a wire and suddenly it woke up.

The Xbee is configured as an END device.

I also found some other answers like set D7 to 0 or disconnect D7 from RTS (which is already diconnected as I use an SMT module) but nothing seems to work.

Any help would be appreciated.

Try disabling the internal pullup/down resistor on the XBee module for that pin. It is mostly being caused by your processor not being able to bring the XBee module to the proper voltage.

I succedded by adding a pull down reistor on that pin, I am not sure if I am able to disable the pullup/down resistor in Xbee.

Yes you could with the PR and PD commands but adding an external works just as good.