I understand your concern. It seems like there might have been a bit of confusion with the event invitations and cancellations. To resolve this, let's try a couple of steps. Firstly, please make sure you have the latest version of Thunderbird installed, as updates often include bug fixes. Secondly, let's clear the event and re-create it, ensuring you add your colleagues only once this time. After creating the event, double-check the recipients before sending the invitation. If the issue persists, you might want to consider removing and re-adding your email account to Thunderbird. This can sometimes refresh settings and help resolve unexpected behavior. Don't worry, we're here to assist you through this.

Hi, hm, I used the portable version and my problem dissapeard... for 2 months. Today I found the same issue with my portable version. OFC I did all recommended by Suram steps...

Regards, Monika