Hi and welcome,
If I’m understanding correctly, when you visit WordPress Appearance > Widgets and add The Events Calendar mini calendar widget, the links to individual events displaying in the widget on the front end are not working?
I’ve I’ve misunderstood your issue, please include exact step-by-step instructions on how to reproduce the behavior and I’d be happy to test.
I see you checked ‘Yes’ to reverting back to the default WordPress theme and deactivating all plugins other than ours as instructed in the Testing for conflicts guide, but can you please confirm this?
Regardless, do you mind testing again ensuring WP_DEBUG and WP_DEBUG_LOG are enabled on your site’s wp-config.php file. Any errors will display at the top of your page as you try to reproduce the conflict. I also recommend right-clicking your mouse and opening the ‘Inspect’ tool to see if any errors display in the console. Note what you find and please include it in your reply.
Thanks and I look forward to getting this issue resolved. Have a pleasant rest of your day! Cheers 🙂