My large A. titanum went dormant last year just at the start of spring. It had been growing a full 12 months, from early spring right around to spring again. Then it went dormant and stayed that way all through summer. Now, after 9 months and just as we're about to go into winter, it's starting to show a sign of growth. I've been digging the tuber out every now and again to check on it. Today I noticed the beginnings of a new shoot. You can see it in the photo, but you need to look hard, LOL.
I've also got a dozen seedlngs that started off in early summer and are about 6 months old now. They'll probably go 12 months like the larger one. Being an equatorial plant they probably don't know what summer and winter are.