When trying to apply another style than default on rows of XLSX file, it doesn't get applied and the code crashes with this message
Call to undefined method Box\Spout\Writer\XLSX\Writer::addRowsWithStyle()
The reason for this problem is that Spout has changed to a new code that cannot be invoked the same old way.
I managed to track it down and solve it, hope it helps anybody who is looking for a solution. (check the changed file to view the fix)
Regarding this issue
The problem is :