XM1110 SPI interrupt

we are working with the XM1110 GNSS receiver. The communication via uart works fine. Now we want to communicate via SPI and use the interrupt to wake up our board. We can receive SPI messages but at the interrupt pin (INT) no activity at all is measurable.
Is the interrupt functionality disabled or does it not work? Or do i need to enable it somehow?
Thank you for your help in advance!