Unable to change access restrictions on pages in Membership Plugin

As the title says, I am unable to change access restrictions on pages. I discovered this when adding a new page, but have subsequently tested it with previously existing pages and found the issue seems to be with pages in general.

I first noticed the issue when I created a new page, confirmed it was not in the positive rules for my visitor level, and yet was still able to access it when not logged in. I couldn't figure out why this might be, so I tried to change whether or not other pages could be seen by a particular user level and it seems I can't. The new page is visible to anybody and everybody while removing or adding permission to see a particular page seems to do nothing to change whether or not a user can see or not see that page (if they can see it before the change, they can see it after, and if they couldn't they still can't).

I've used the verify membership tables tool (though not repair) and it says everything is okay. I am able to make other changes to access restrictions (specifically I tested the ability to add and remove items to/from the menu) so it appears to only be an issue with restricting pages.

Any help would be greatly appreciated. Thanks.