Hi Kevin!
Thanks for reaching out to us! Let me help you with that issue.
I’m getting a 404 page on both of those links you shared.
First, I’d recommend you try refreshing your permalinks structure to see if any difference.
If no difference, then this could be related to a theme or plugin conflict, so to narrow the problem down please go through the steps provided in the testing for conflicts guide > https://theeventscalendar.com/knowledgebase/testing-for-conflicts/ and let us know what you find in the process.
We always suggest to setup a dev/staging site so you can test things out and make all plugins, theme and WordPress core updates without disrupting the live site.
Let us know how that goes.
Thanks,
Victor