I was wondering if frost knocks this back annually, or some years (as much as you can tell from a 3-year relationship?) If so, it's "Syngonium-ness" could be something you'd never see, the vine growing. You'd just have basal (re-)growth.
And yes, Caladium leaves are so similar. Like I said, I looked at this plant for years, thinking Syngonium was Caladium, then decided I could see it better elsewhere, so got the shovel out and - surprise! No bulbs. If there is a bulb, it's not Syngonium, to the best of my knowledge.
Either way, I love it, miniscule plants are some of my favs!
Thought that was a Tillandisa. I got one and put it in the crook of a little Dracaena tree. Looks like a mama with a baby in a pouch, IMO - LOL!
Forgot to say, a close examination/comparison of leaf veins may help, as well as petioles.