Supernatural's Groundhog Day Episode Explained A Season 15 Ending Plot Hole 12 Years Earlier 

screenrant.com -BY MANDY CARR -Supernatural tied up everything in season 15, but it also ended with a plot hole. Fortunately, an early episode in the series explains this.
Keywords: supernatural, groundhog day episode, explained, season 15, ending, plot hole, 12 years earlier