Training manual doesn't activate
Are you unable to place those 7 trait points into any line? If so they it does sound bugged.
If you CAN place them then you have already unlocked what the manual unlocks.
They do not give trait points nor do they reset your trait allocation beyond the first use.
If you want to reallocate trait points you have to pay the trainer, it’s one of the options. The manuals only open up the trait lines so you can go further down them.
In case you ended up with an extra manual, don’t destroy it. Put it in the bank and save it for your next character.