It's working fine for me and the frames are all as they should be.
Even when I download the above GIF to my comp, it doesnt play the last frame. It looks fine on the Chrome and when I preview the file before saving.
»It looks fine on the Chrome and when I preview the file before saving.«
So where does it display incorrectly? The faulty Mac preview?
Yeah, when I preview from the Finder. I just needed to confirm that this was a Mac issue and not a Photoshop issue. And.... it looks like this is a Mac issue. Everyone is viewing the file correclty.
You last frame should be off the frane before the last should be on and delayed 10 seconds.