CM1150v comcast link aggregation suddenly failed after 8 months

[Badexperience]

The CM1150v was connected to an ORBI RBRE 960 via Xfinity.  Link aggregation was active and speed tests showed a regular download of 1300+ or -.  After approximately 8 months, the ORBI would not connect with link aggregation; in fact, the ORBI would not draw an address from dynamic DHCP.  In order to re-establish a network link,  the ORBI had to be set manually to the modem's address.  once re-linked, further resets allowed the DHCP to function again.  Any attempts to re-establish link aggregation results in the ORBI losing connectivity. 

I would assume one of the three is possible:

1) Xfinity changed the programming and is causing the issue;

2) The CM1150v either has a failure or new firmware was pushed to it in late January;

3)  The ORBI has a mechanical failure as the software has not changed since October.

Does anyone have any knowledge of software pushes or programming changes?  Anyone experience the same?  Any help will be greatly appreciated.

[plemans]

Does the modem work if link aggregation is disabled? 

Have you tried a factory reset on both the modem and the router? 

You can even try downgrading the firmware on the router if you suspect its a firmware issue on the router. (sadly, not the modem)

[FURRYe38]

What have you tried to resolve this? 

Power cycled the modem and RBR OFF for 2 minute then back on?

Any factory resets on both units and setup from scratch?

What CAT# LAN cables are you using between the modem and RBR? 

What FW is loaded on the modem and RBR? 

Any recent updates to both units? 

[Badexperience]

The ORBI does work only if LA is disabled. The ORBI was factory reset. The system was downed for several minutes with the cv1150 be out up first. I was avoiding factor resetting the modem as the Xfinity tech support can be painful in reprovisioning the cv1150. I am saving that as a last resort, just before having am ample amount of wine and a long tv show to watch as they go through their scripts. I kind of resent having to jump on my left foot while patting myself on my head as part of their process.

[plemans]

A factory reset on a modem shouldn't require re-provisioning. It should auto-provision because the mac is programmed into the ISP's system already. 

The checking the cables is a good option as well. If one cable is sketchy, it'll cause issues.