LACP Issues - 1G Cable

I am running into an issue with LACP from my cable modem to my router. I have the Arris SB8200. After about 24 hours the connection slows to a crawl (5mbps with higher latencey). An disable/enable of the interface (or physical unplug, plug back in of the ethernet cable) fixes it. To troubleshoot, I disconnected the second ethernet cable, though LACP is still enabled on both sides.

 

I thought it was a router issue. But then I read a review on a large retail website for the Netgear CM1200, and it sounded strangely familiar:

 

"So i run this cable modem with LACP enabled (two 1Gig connections from the modem to my routers WAN ports to give me more bandwidth) to my new Netgear RAX80 WIFI 6 router. I thought I was having issues with the router as my download speeds would slow from 1024mbps to 12-20mbps over a 24hr period. After a reboot the speeds would be normal. I returned the RAX80 but the issues persisted. It turns out this is an identified problem with the firmware version Xfinity has deployed to the CM1150V cable modems (you are dependent on your ISP for FW updates to the modem) V2.02.04 is the newest version Xfinity/Comcast deploys and it has a bug relating to LACP.

**UPDATE 1/14/2020**
I disabled LACP and with the single connection to my router the speeds stopped slowing to a crawl. While I wish I could use the features I paid for, Netgear has updated their firmware, but Comcast/Xfinity hasn't approved it yet, but I cant blame Netgear for that."

 

Has anyone gotten LACP to be stable on either an SB8200 or CM1200???

 

Signals are all excellent on the Cable Modem.

 

I am not looking for "why bother" or "you don't need LACP" answers. Yes, I know you only need 1G ethernet cable for 1G internet. That is not the point. The point here is Comcast pushed down the firmware to enable LACP, but there appears to be an issue. I have gotten nowhere with Xfinity Support chat. Even had the technician claim they were a Level 2 escallation engineer and lie to me saying that Comcast does not push down firmware or config files to customer owned cable modems! And then they wouldn't escallate my call when I asked. 😠