Note that this is primarily a user to user support group. Can you provide more information? Are you using gigabit networking equipment? Is the slow transfer happening over WiFi? If so what is the WiFi speed/connection? Are you transferring across the local network or to a remote My Cloud? How are you measuring the transfer speed? What operating system are you using? What troubleshooting steps have you tried?
Basically to get assistance you will need to provide more information.
Further see the following which explains why one might in certain instances experience slow copying speeds.
https://community.wd.com/t/before-you-pack-up-your-wd-and-return-it-lets-talk-about-copying-speeds/91887
