Error Message on mobile view

Hello everyone,
im getting a HTTP 403 Error, when I am trying to change the Month or only show one Category.
But this problem is only on the mobile feed in Desktop view is everything fine.

I’m using the plugin Version 2.5.2.

I hope you can help me.

Fabian Seelbach

https://wordpress.org/plugins/all-in-one-event-calendar/