Turn signals all quit at once!
Yes, so far, it does sound like the turn signal is working. Here's what I would do now...
If you can get to the emergency flasher, see if you get the same results on that flasher. You will use the emergency flasher button, rather than the turn signal, obviously, but this should tell you that you're reading it correctly.
After that, I would replace the turn signal flasher.
If, for some reason, that does not fix it, as I mentioned earlier, I would remove each bulb, one by one, and match it against the listing in the owner's manual or shop manual, just to make sure that none of them have an incorrect one.
It honestly sounds though like a flasher will take care of it.
Well, good luck. I'll check back later to see how you made out, but right now I have to get going, as I have some Christmas joy to share with some less fortunate families in the area this afternoon.