The Jottacloud remote is using the Jottacloud-API unofficially. There is no documentation or any kind of "stable" use of it. They change it from time to time and then we have to catch up.
And now it seems they have changed the way the tokens are handled and this cause trouble for anyone using Jottacloud with rclone.
Unfortunately you will have to wait for some one to step in and fix this. Until then it's considered broken and you would need to use the official Jottacloud tools.