Etar calendar app on my phone dvice
I think this is the most probable explanation. Somehow dtEnd was set to zero instead of null, which caused the problem. Normally, only calendar apps do such modifications.
do you think there’s something you can do on DAVx5 side so that one false event wouldn’t block syncing other events?
Unfortunately, this is more complicated than it sounds. At the moment, uploads are performed before downloads and upload errors interrupt the sync process. The reason is that incomplete uploads might have later impact on synchronization. For instance, the synchronization would see that the server has another version of the event and overwrite local changes (because the server always wins); or even delete the whole event if it hasn’t been uploaded once before.
So, while it might be possible to optimize this, it would be a complicated change and at the moment that’s not a priority for us.