me too same problem… after update openhab 3.3.0 with new netatmo bindinng it is OFFLINE. I tried many times to give grant with http://:8080/netatmo/connect/<CLIENT_ID > but the state is OFFLINE.
I forgot to repeat my solution. The problem was a file with the refresh token in the system. I renamed the file with extension .thing and create a newe refresh token and it works. In the last step I changed the refresh token in the .thing-File.