parallax section not working in mobiles when image set as background full

Hey there i am using shapely theme for one of my project i replaced the default shapely parallax widget with widget plugin provided at this thread
the plugin is working great on desktop but when i set the image as background full in parallax section in some mobile browsers like google chrome and firefox the scrolling becomes rough and in some mobile browser only half of image is displayed.
but when setting the image as “background small” everything works great.

please help me solve this issue
my site is at

Hi @ethann,

I hope you are well today and thank you for your question.

It’s known issue as reported in the following topics which will be resolved in the future version of theme.

Best Regards,