Ok, I redid the tests. It appeared to be related to 2 plugins. However it brought to light another issue. I listed the two plugins below.
Check out the site now. The new issue is that when you click previous once it will work correctly. However check the link of the previous button again. The tribe_paged=1 is still set to one so the pagination does not work.
Second issue. Click the main events page and click the previous button again once. Check out where the next events is going to. It switches to upcoming events when it should show you current events.
Third issue. Go to the main events page. There is no upcoming links pagination when we know it exists from when we hit the previous page.
Just a reminder this is all stock except for some css tweaks. Plugins below.
Post Types Order
Posts Order and Post Types Objects Order using a Drag and Drop Sortable javascript capability
Version 1.6.8 | By Nsp Code
Simple Page Ordering
Order your pages and hierarchical post types using drag and drop on the built in page list. For further instructions, open the “Help” tab on the Pages screen.
Version 2.2 | By Jake Goldman, 10up