Titantic Hydra bugged on Trundle

I've been playing a LOT of Trundle recently. But I've noticed that using the Tiamat passive doesn't do anything bad, but if I upgrade it to Titantic and then use it, for some reason my next auto attack after is like half attack speed or less.

This used to be a bug back in the day so idk if it was just accidentally left in Trundles kit or what