Hi Jean-Philippe!
I’m sorry you are experiencing that issue. Let me help you with the troubleshooting.
First, please make sure you are using the latest versions of our plugins.
After that, please share with us your system information by following this guide > https://theeventscalendar.com/knowledgebase/sharing-sys-info/. We’ll see if there is anything strange that would indicate an error from there.
Also, could you please share with us a screenshot (in a private reply if you’d like) of the edit event page while editing the existing ticket? We’ll try to reproduce the issue on our end and see if we can reproduce.
Thanks,
Victor