Events + Integration addon for Membership 2 pro not working

I hope someone can help.

We are using Events + together with Membership 2 pro plugin and for some reason they are not working along well. If i enable the Events + addon for the membership 2 pro, the payment button don't show up on the event page. if disable the addon, the button show up but when you clicked, it doesnt do anything and just refreshing the page - I'm using PayPal sandbox for testing so it should redirecting to the paypal sandbox checkout page but it did not.

I'll enable support access in case someone want to peek on our setting.