I don't remember it being an island. The Dan Ackroyd / Aykroyd one is explainable because you can find lots of sources where it's either Ack or Ayk so I thought it was Ack likely from the sources in error.

Why I like the Mandella effect however is it literally is a plot to a novel I was once writing where only one person noticed these small changes occurring in reality because the very fabric of that reality was collapsing. It's exactly the real life mandella effect idea. Wrote the novel back in 1989 but lost it on a hard-drive failure before I understood the merits of backups *sadface*