problem with touch button in UI .

greeting everyone , i have been searching for a lot of time and am tired with this problem .
i set up 2 buttons in UI canvas . these buttons to use function to make make my player move : one to left
the other one to right

i used the event trigger ( instead of onclick ) i want to use it in android so if am touching the left arrow button the player starts moving ( and it works fine ) but if i release my finger from the mobile
the player is still moving although i used another event if pointer exit the button to stop the movement of the player .

note : it works fine on pc with mouse .

– my guess is that on android if you touch somewhere in the screen to pointer stays there even if you left your finger out of the screen : and what i need to do is to use something that tells it if am no longer touching the screen dont keep the pointer at the button – that is only guessing

is there a way around this ?? please help i know i wrote a lot but i wanted to describe my issue .
thanks in advance .

1.add Touch input module component to EventSystem
2.check Force module active
and maybe you need disable Standalone input module