STM32F769 IsoINIncomplete callback gets called multiple times in a row but OTG_DAINT register has the value 0x00000000. What can be the reason?

[MGuen.1]

Hi, I am working with the STM32F769i-disco board and develop an usb audio 2.0 device (a microphone array). When I start a recording application on the host pc, the IsoINIncomplete callback gets called multiple times in a row but the OTG_DAINT register has the value 0x00000000, which means that no IN endpoint caused the interrupt (if I understand it right). Has anyone an idea what could be the reason for that? :grinning_face_with_sweat: