hi all,
FYI,
this is known issue with JetPack-5.0 Developer Preview version.
since the fan speed is controlled by the nvfancontrol systemd service. however, it sometimes the nvfancontrol service is started before the required fan driver gets loaded, which makes the nvfancontrol not able to control the fan speed.
you may workaround this by issue the command $ sudo systemctl restart nvfancontrol to resolve the issue.
furthermore, we have fixed this issue in the next JetPack public release.
thanks