You can use the forum search feature, magnifying glass icon upper right, to find the various discussions on the Uverse/My Cloud issue. Here is one such discussion.
https://community.wd.com/t/cant-connect-my-cloud-using-att-uverse-1gig-fiber-service/140412/
The workaround involves using a cheap gigabit switch (or spare gigabit router if one is available) and connecting the My Cloud to the switch then connect the switch (or spare router) to the AT&T Uverse router/gateway.
