ICALENDAR sending multiple event confirmations for every single meetings

Hi

I have been using Icalendar for years with a gmail address and I never had any issues.

I am now using it with my work domain email address and every single time I either setup a meeting or accept a meeting sent by one of my clients, Icalendar sends multiple "event update" emails to them but also to me. If I open an existing meeting in Icalendar to check something up, it also sends multiple "event update" emails.

It is a huge issue and it really annoys my clients. My business partner, who uses a recent MacBook Pro, has the same problem.

We have had the problem for over 3 years now. We both removed our work account from our iPhone and this doesn't solve the issue.

If I look at the "confirmation emails" I receive and that my client receive, the email title says "Updated: actual meeting title." and there are 2 attachments "event-update.ics" in the body of the email.

I am using a MacBook Pro (13-inch, 2017, Two Thunderbolt 3 ports)

MacOs Monterey 2.6 - but I have had these problems with previous versions

My domain is hosted with O2switch.

We have contacted O2switch but they say it is an app problem.

Is there a way to fix this?

Thanks a lot