Shapeshifters with Titanic bug?

Hey there. So I played a few games, trying out 6 shapeshifters comp with titanic and warmog’s. I put the items on either a 3 star jayce or 3 star shyvana. Before transforming their hp’s were in the 2000’s but when they transformed they went into the 5000-7000’s. The thing is, titanic damage didn’t seem to change at all; before and after their transformations. Maybe it takes the initial max hp and forgets to register the bonus from shapeshifter bug? I’m confused.