IceTV lists Petra: Lost City of Stone (SBS 19:35, Sun, 1 May) as a single show, not a series.
Is it the episode of that name of History's Mysteries from 2001, the episode of that name from Nova from 2015, or something else entirely? There's something completely different in that timeslot on 8 May, so is SBS just grabbing a random episode as a filler?