Hey Susanne,
The fact that issues persist despite updating is even more evidence that a theme or plugin conflict is at the core of your issues. I would recommend, then, essentially the same steps as in my other reply to your original thread:
First, you should send us your “System Information”, which you can learn to do here → https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Next, I’d recommend running through our complete set of troubleshooting steps here → https://theeventscalendar.com/knowledgebase/testing-for-conflicts/
As noted before, the information from both steps here will be immensely helpful for troubleshooting and finding the cause of these problems.
Let us know what you find!
Thanks,
George