Template variables not saving even though it says 'saved'

Using version 2.7.1 and I am getting intermittent instances in various sites where template variables are not saving. When I click save, it get a message saying the document was successfully saved. But when I visit the document again, the changes made to the TVs are not there. This seems to particularly affect TVs where the input option is set to Image.

Any help would be appreciated as this is causing lots of issues.

Are you referring to the editing of the actual TV under the elements tab or is it whenever you change values of a TV inside a resource?

For the last case I remember this happening to me when the user who accessed the resource didn’t have the proper access permissions for example to the given media resource of the image.