Bug: Lightbox pop-ups in Firefox, options are covered and not usable

Bug: Lightbox pop-ups in Firefox, options are covered and not usable

When selecting certain options that triggers a lightbox pop-up (e.g. when attempting to deactivate a CRM user in Users & Permissions) the pop-up appears behind the gray interface. This results in it being unable to click on or interact with in any ways. This problem seems to be pretty consistent across lightboxes in Firefox, but works in e.g. Chrome.