My Cloud Home Offline

I cannot figure this out! My device was working perfectly for months then last week it was showing as offline. When I rebooted the gateway, the device was working as normal. Then, after about 30 minutes, the device showed as offline again. I rebooted the gateway again and again, the device appeared online for a few days. It appears to be going in this cycle of online/offline and with a gateway reboot, it comes back online for a while. I have opened up ports 80 and 443. A new gateway is on the way but why did it start this in the first place?

Interesting find today. I replaced the router based on AT&T’s recommendation. It worked just fine for 24 hours exactly. Then, again, it went offline. This time I opened up ports 80 and 443. Nothing changed. Then, I changed the the transmission capabilities of each ethernet port to gigabit full duplex and miraculously, the drive was instantly visible!

puoi spiegare meglio x favore?
grazie