Have had a set of three deco x60s for ~1 week now. Already twice the deco has lost connection to the modem (or at least shows as unconnected).

1. In both cases there was no internet outage.
2. Restarting the deco solved the issue.
3. This issue is with the source router. The other two are wire backhauled to the source, but all three loose connectivity, so layout of other two is no factor.
4. The modem is a Xfinity XB7 in bridge mode.
5. I replaced the ethernet cable after the first time just to confirm in wasn't an issue with the cable. 

Any suggestions?

Much thanks!