Please note there is a difference in nature between SMB(CIFS) vs NFS. NFS starts writing immediately to the filesystem and writes as long as there is space. However, CIFS continuously tries to reserve the space before copying (folder/files) to the target. Please check: How much data are you trying to copy over ? How big is the largest folder/file size?
Also, check or share the volume & share-level settings for the SMB(CIFS) at NetApp side?