Hi and welcome to the forum
It could be a bad key on your keyboard. If you have a desktop PC, try another external usb keyboard. Does the t still fail?
If you have a laptop, disable the internal keyboard and plug in an external usb keyboard? Does the t still fail?
If the t works on the 2nd keyboard on the desktop PC; you've got a broken t key on the original keyboard and it should be replaced.
If the t works on the external usb keyboard on the laptop, the t key is broken on the internal laptop keyboard and that should be replaced.
If the problem persists with external keyboard on either the desktop PC or the laptop, you could have failed hardware and you need to test it. It could also be Windows corruption which...