Ever had your TP set to a hotkey ( obviously )
And it just stops working? It does the animation, but releases no TP.

First, make sure you dont have another tome in your stash ( that was my problem )

The trick is so open up some inventory space, grab your tome, buy some separate TP's to keep in your inventory, buy ANOTHER tome of TP
Go out and hit your hot key, see what TP it uses, it could be you set it accidentally to your other tome or a single TP, then reset it to your original hotkey.
This fixed mine.