Play my flip book material

Hi everyone.
I try to use a flip book material on my level. I would like to play him with a condition and juste once …

In fact, In the material i have a scalar parameter = 0 “LoupOn1” by default, this parameter control my animation’s speed. My node time = 5 because my animation lasts 5 sec.

Then in my thirdperson blueprint , I say, If you see my wall1, then you change my first paramater scalar you wait 9sec and you change my second parameter scalar “LoupOn1” = 0.2, you wait 5 sec (time to play my animation) and then this parameter is again = 0.

I need play my flip book just once and only when my girl is passed.

Good : Good - YouTube

NotGood: NotGood - YouTube

In this videos:
In the “good” video it’s work because as soon as my level begins, i look my “wall 1” so the condition is immediately true. In “notgood”, i wait 1 or 2 sec, and you can see , the flipbook is disturbed (out of sync ?).

My supposition is , my flip book is played even if my scalar parameter “LoupOn1” is equal to 0 …

… Sorry for this novel. If someone knows how to play this flip book once and only when my girl is passes (it’s a decal actor too)… I hope it’s clear ^^""" sorry