Basically, 2 in-frame popups are rendering from the Maintenance > Preventive Maintenance > Plan Work record.
To reproduce, create a new Plan Work record (Add button) and go to the PM Schedules section. Then click on the Add button. A popup will render for the PM Schedules. Then inside this popup, click on the Create Recurring Pattern link. The new popup will render inside the existing one, and that will have part of it off-screen, sometimes preventing users from selecting a radio button for the recurrence.