That ‘testing’ agent is likely an older version of what we’re eventually going to release to fix 4.9 compatibility, I wouldn’t bother with it at the moment.
Until we make that release (likely in the next week or two) – I would stick to the 4.4 Linux kernel and the agent downloaded by going to Add New > Device/Widget > Single Board Computers > Raspberry Pi in Cayenne. You can update to the 4.4. kernel with the following command:
sudo rpi-update 52241088c1da59a359110d39c1875cda56496764
I know you said you’re having some issue with the GPIO not displaying on 4.4 - if you ran the above command to downgrade, have you also rebooted your Pi afterward? The kernel will not change over until the next boot. I’d say reboot, check
uname -a to verify your kernel version, and if it still doesn’t work, let me know the output of
service webiopi status