This is a known bug in pybotvac that has reappeared since we merged the OAuth changes.
I am not quite sure what is the exact reason for this error. As a result, we get incorrect or at least undocumented data from neato, so we run into a parsing error. An upcoming version of pybotvac will work around this problem. For now, please check your account for broken robots at https://neatorobotics.com. We know of users who were able to fix this issue by deleting old or unknown robots from their account.
When instantiating a new OAuth integration in Home Assistant, make sure you start only one configuration flow at a time. Even though you can click “Open Website” several times, press it only once and wait until this flow is complete.