Failure to thicken...

I just noticed today that Vanilla flavored (I dont know about the other flavors) Jello Instant Pudding is vegan if you make it with something other than cow's milk. I tried it with soy milk but to my surprise it didn't thicken and I am now left with little bowls of yellow syrup. I looked this up online and it is apparently a common problem, one person suggested that using half coconut milk/ half soy milk solves this problem.

Has anyone else tried this? Suggestions?

G.