Good evening Saskia and welcome to the Events Calendar Support forum!
Thank you for reaching out to us.
I would love to help you with this topic.
As you might have found out already, we currently do not support tickets for recurring event.
That being said, we are working hard at making this feature work properly and offer different options on how it works.
If all goes well, we would like to be able to release this feature by the end of the year.
In your specific case, if I understand correctly, it sounds like you might be using some kind of custom template. Can you confirm ?
As a first troubleshooting step, could you please provide us with your complete system information in a private reply using the instructions found in the following link?
https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Secondly, can you tell me if you have the same behaviour with a default WordPress theme such as twenty-fifteen ?
Best regards,
Geoff B.