My website has a different header template for default and posts, and the event single pages need to use the posts template but are forcing to default which does work with the page layout. I have reached out to my theme developer and these are their comments:
It seems that the plugin is getting the page template, but, by default, it should get the post template. I even try to add a specific template on the child theme, but it seems that the plugin forces the page template.
Can you please reach the plugin author and ask why is this happening and how we can override it?