Calendar Invite continues to send notifications

For a long time, when I send an invite from my iPhone calendar to individuals, they respond and I then get a notification from the inbox of the calendar, where I have to go in and then click ok to clear it.

My husband who is an android user (boooooo!!!) always then receives the invite again. If he accepts again, I then get a notification, go in and click ok, and it resends the invite to him. Very annoying, but we just put it down to different phones as I haven't had anyone else comment on this happening to them too.

However, on the weekend, I sent an invite to a group of friends (all of them are iPhone users) and as soon as I received the accepts, I would go in and click ok, and it would resend to all of them. You can imagine their annoyance when 8 people were constantly being bombarded with constant invites.

If I don't click OK, I get an unread icon on my calendar, which I don't like.

If I click into the invite and don't even update or do anything, it will always resend the invite. It's so annoying!

Any ideas as to what is happening and how to stop the calendar resending to all invitees?

I am on the most recent iOS (17.4.1)