I finish the raw edges (either serge or zigzag) of the FQs and wash them.
Look at the threads after they are washed - they probably are trying to be perpendicular to each other.
If the fabric got misaligned during the processing, it was probably wound on the bolt off-grain. When it was cut, it was probably cut perpendicular to the fold or selvage - but the crosswise threads may or may not have been perpendicular to the selvages.
Which is why the FQ looks "wonky" after is is washed. It went back to what is "normal" for that piece of fabric.