Hi,
Sorry for the issues you are having. I can help troubleshoot this with you.
That url you gave is not a valid url to visit (it is only for ajax scripts to use to get data) and it appears something is redirecting to that url incorrectly on the front end so that looks to be the source of this issue.
On the list view you have a numbered nav of Page 1, 2, 3 etc..
However, usually we have only a Next and Previous Events links and not numbered such as that.
Do you have a plugin or custom function that is providing this? Or is it coming from your theme?
If you follow our testing for conflicts guide:
https://theeventscalendar.com/knowledgebase/testing-for-conflicts/
Does that narrow down the cause of this?
Let me know thanks.