GRN status is still not showing completed in WMS.

This happens when the put away is not completed for all the products from GRN. You can see the list of SKUs that are pending for putaway under New & In-process state in Inbound 

Module>Putaway state. 

Screenshot below for reference: 

We hope the details above were helpful for you. Please feel free to share with us if require further assistance and will be happy to take it up.