I am using openHAB 2.4.0 (also had the issue in 2.3.0) with a Nest Hello.
Over all, the binding works. But often, the snapshot url changes, the binding has the new url (I can check that in PaperUI’s control page), but it did not fire an event.
The result is that I see no entry in the mysql database (records all changes) and habpanel does not update the image until I reload the browser page.
There is also no change event entry in the events.log.
Anyone knows how to debug and/or fix that?
Just made the observation that the binding only fires changed events for the snapshot url when the camera reports a motion event. The timestamps of the motion events and the snapshot url changes are identical.
I do not think that this is the correct behavior. Snapshots and motion events do not have anything to do with each other IMHO.