I have copied the code from your running project to my project , exactly the same way mention by you.But it is not working in my code . It give me error while adding like -
IndexOutOfBoundsException: Invalid item position 0(0). Item count:0
I have attach the below screenshot of my error

This occur in the customLinearLayoutManeger class on this specific line
View view = recycler.getViewForPosition(position);
it is not adding the view for my recycleview.
I have copied the code from your running project to my project , exactly the same way mention by you.But it is not working in my code . It give me error while adding like -

IndexOutOfBoundsException: Invalid item position 0(0). Item count:0
I have attach the below screenshot of my error
This occur in the customLinearLayoutManeger class on this specific line
View view = recycler.getViewForPosition(position);
it is not adding the view for my recycleview.