Thunderbird does not support O365 calendars in the first place, so please don't post in this bug if you're having a calendar problem. If you have a problem with an add-on, report that to the add-on author -- not here, where we can't do anything about it.
Bug 1810760 Comment 99 Edit History
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Thunderbird does not support O365 calendars in the first place, so please don't post in this bug if you're having a calendar problem. If you have a problem with an add-on, report that to the add-on author -- not here, where we can't do anything about it. Bugzilla is also NOT a place for tech support.