Massive Graphic And Massive Lag on Samsung Galaxy A Series

Hey everyone , i have developed an android game , it works fine on older devices like galaxy note 3 , S5 , LG models and others … The problem is ; the game massively lags on Samsung Galaxy A series , Like A5 2016 and A7 , And also it has like , Console’s graphics in the mobile device , I mean it seams like there are no optimizations on these (A series ) devices and cause this massive lag. What can be the problem ? Am I missing something ?