Hi @aswatband,
Appreciate you getting back to us with the URL here. Sorry to hear that you are having this issue. Please make sure that the plugin is up-to-date. Could you try flushing your permalinks and see if that makes a difference?
See the article here with the heading Flush Permalink:
https://theeventscalendar.com/knowledgebase/k/fixing-http-404-errors/#flush-permalinks
Moreover, I noticed that you are using SiteGround as your hosting provider, could you also try and flush your site cache as well?
See the article here on how to Flush Cache with SiteGround:
https://www.siteground.com/kb/clear-site-cache/
Lastly, I’m curious about your slug details, Events > Setting > General Tab > Events URL Slug & Single event URL Slug — could you provide me a screenshot of what you see on your end. Make sure they are unique, and slug is not being used on other post/pages, please flush permalink when updating these fields as well.
See the screenshot here:
https://share.getcloudapp.com/Bluoq2Om
Let me know how it goes on your end.
Best,
Abz