Good afternoon.
Problems in synchronization
The first day I connected Trello to the Calendar, all events, tasks, etc. displayed successfully. And all changes and new notes are no longer displayed, both in the browser version of the calendar and in the mobile application. When relinking Trello to the Calendar via a new URL, the Calendar is updated to the current one, but the new test task with the date set was not transferred to the Calendar.
In Trello, in the "Sync Queue" I found the error "Update notification: local... State: failed...". Not sure if this is related to my request as I know that some email notifications from Trello itself are blocked for me, which are in no way related to Google.
The error is simulated only in the calendar update, that is, synchronization takes place only at the moment of binding to Trello. I ask you to check what the desync is connected with? How to eliminate it? Google tech support was sent to you in Trello.