Forum d’assistance Thunderbird

I am running Thunderbird 115.11.1 on Windows 11 and no matter what I do I simply cannot send a calendar invitation. I click to create a new event, I add the email addresses of the attendees, I make sure to click the checkbox to send out invitations and as soon as I click Save and close nothing happens other than the addition of the event to my own calendar.

Yes, I have checked whether my email address is included in the calendar settings. Additionally, there is nothing in the Sent folder after clicking Save and close.

I can edit and add notes in the description of self-created calendar events. However, invitations are not editable. Is there a way around that, perhaps an extension that you know of? ("Tasks" are not an alternative here for me.)

In the past I had used Thunderbird for both email and calendar for multiple accounts. I just downloaded Thunderbird onto my laptop (PC running Windows 11) and added all of my accounts and they are all synced. However, I can't edit or delete any event from any of those accounts directly in Thunderbird, although if I make changes on a different device they will sync and update properly. I never had this problem when I used Thunderbird before. I didn't see any permission settings that would allow me to do this so I'm stuck. Any suggestions? Thanks!