Issue with menu cut off

Hi There,
I like your plugin, however when it is activated it somehow interferes with my menu system when I’m adding new menu items. When I add an item to quite a long menu, the browser hangs then returns a 404. I hit reload and the menu admin page appears with no changes. It happens as the menu gets to a certain number of items. I turn the Facebook Open Graph, Google+ and Twitter Card Tags plugin off, and the problem goes away, turn it on and it is back. Both my sites are doing it. (The other site is wordpress 4.0)
I know this is very odd, just thought I would mention it.

https://ww.wp.xz.cn/plugins/wonderm00ns-simple-facebook-open-graph-tags/