Everything seems fine on the firmware side. Honestly, I don’t know. We currently don’t have a RPi 5 for testing. We did test the firmware under RPi 4 with Bookworm and the GPIOs are all working. Not sure if something is different with RPi 5. If you want you can send a support ticket at:
support.opensprinkler.com
and arrange to send us your RPi 5 so we can diagnose the issue and make sure it works then send it back to you.