Can save some settings, not others

I moved some of the icons around, unchecked a couple of boxes to hide that icon, and some of the changes are saved when I click Save but some aren’t. Can’t seem to uncheck the box for Pinterest. Also trying to delete the “To” field contents for emails (why would I want to set the “To” field, anyway?). Just downloaded and am trying for the first time today, not upgrading from any previous versions.

https://wordpress.org/plugins/osd-social-media-sharing/