Raspberry Pi 5: invalid GPIO 9

[igo]

Hi,
after migrating to RPi5 from RPi4 I cannot run mysgw:

pi@pi:~/projects/MySensors $ ./configure --my-transport=rf24 --my-gateway=mqtt --my-controller-ip-address=127.0.0.1 --my-mqtt-publish-topic-prefix=mysensors-out --my-mqtt-subscribe-topic-prefix=mysensors-in --my-mqtt-client-id=mysgw1
pi@pi:~/projects/MySensors $ make
pi@pi:~/projects/MySensors $ sudo ./bin/mysgw 
Aug 27 15:16:32 INFO  Starting gateway...
Aug 27 15:16:32 INFO  Protocol version - 2.4.0-alpha
Aug 27 15:16:32 DEBUG MCO:BGN:INIT GW,CP=RNNGL---,FQ=NA,REL=1,VER=2.4.0-alpha
Aug 27 15:16:32 DEBUG TSF:LRT:OK
Aug 27 15:16:32 DEBUG TSM:INIT
Aug 27 15:16:32 DEBUG TSF:WUR:MS=0
Aug 27 15:16:43 ERROR Could not open /sys/class/gpio/gpio9/direction

Any idea what is happening or how can I debug it? I found this which says "raspi-gpio is deprecated and doesn't support Pi 5".