After enabling "Enable SMB 2 and Large MTU" on the Synology NAS and adding vers=2.0 to mount options in /etc/fstab, the transfer works OK.
Thank you in pointing me in the right direction.
After enabling "Enable SMB 2 and Large MTU" on the Synology NAS and adding vers=2.0 to mount options in /etc/fstab, the transfer works OK.
Thank you in pointing me in the right direction.