Not all sidebars show in overview

For a website we are using your Easy Custom Sidebars plugin. However the customer has a lot of sidebars. I think near 200 (1 for every country on the site). However, in the overview screen it doesn’t show all sidebars. We have the feeling it stops executing after a certain amount. Is there something we can do? Cause now we can’t edit the last sidebars in the list. It cuts off from about the L.

Hope to hear from you soon!