On tablet so can't check capx, but guessing you're using bullet for background, try using leap
Also, I wouldn't call that a platform game, more like an endless flyer.
Thank you for your answer.
I don't use bullet behavior, I just change Y position of background in every Tick,
I replace my scrolling code with lerp function but no difference, by the way, I had tried bullet bahavior and 8-direction for scrolling too!