Howdy Pascha,
I would love to help you with this.
The view you are loading there, Month view, can place a very large load on your database. To help alleviate this we created the Month View Cache. Do you have that enabled in WP-Admin > Events > Settings > Display ? If not, could you try enabling it?
Even with that enabled though we have noticed one portion of the page that is not getting cached in the latest version of The Events Calendar . It’s the JSON-LD results. For now we advise disabling JSON-LD on month view if you are hitting performance issues. You can do that by pasting the following snippet at the top of your theme’s functions.php file. Replace the opening “<?php” with this snippet, as this snippet includes that opening tag.
https://gist.github.com/elimn/9ce1c3e64d060b758e22627b815455ae
With that snippet in place, and the cache enabled, are you seeing much faster page load times on Month View? The first load might be a little slow while it generates the cache, but after you reload the page a couple of time I expect it will speed up dramatically. Does it?
Cheers!
– Brook