Is it possible to tongue notes w/o changing embouchure

No matter how carefully I tongue a note, especially, if it’s a fast tune, my lower jaw keeps moving, and the result is that the embouchure becomes unfocused.

Is it possible to tongue notes on flute without moving the jaw or altering the embouchure in the process?

Yes, patience. Also you might try glottal stops, if you
aren’t using them already. try a search.
I use both.