Creating extra layer when export jpg

Hi all, I’m having a problem where when i want to export a frame in jpg. it automatically create extra layer which then i cannot get an exact size just like the design. please do help
![boost - click|162x80]
image
(upload://17cNA9SHZcQGCPIbphJbhxPX8oe.jpe
as you can see there’s extra layer when i export

image
sorry here’s the export img