Here are the facts:
Front= "THE SENTENCE ON THE OTHER SIDE OF THIS CARD IS FALSE."
Back= "THE SENTENCE ON THE OTHER SIDE OF THIS CARD IS TRUE."
You can start with either side, it does not matter. Let's use "-n" to specify deniability, and let's start with BACK:
Back = Front = -nBack = -nFront = -n-nBack = -n-nFront = -n-n-nBack = -n-n-nFront = -n-n-n-nBack = -n-n-n-nFront = etc. = etc.
It is an infinite loop of deniability. By starting with BACK, first, assumes truth until the loop cycles back to BACK and deniability begins, infinitely. Starting with FRONT initiates the infinite loop immediately, but intuition of using the FRONT, first, should call the question of "when did this start in the first place?" (there was no beginning, it has always been), because we could have started with BACK initially... See how this works?
This problem has two flows: a reverse flow