CM1000 performance issues after 1.5 years

Has anyone noticed issues with the CM1000 performance after awhile of having it running? I got mine at best buy just over a year ago and now it seems like it keeps having connection issues. I thought it was my ISP at first (comcast) or my wifi mesh (google mesh), but after some trouble shooting I narrowed it down to the router. If I reset the cable modem I get test speeds in the 700Mbps range, and that will last for a couple of hours then slowly it will start to go down. By the next day I am getting speeds of about 1Mps or less, until I can no loger connect. I reset the cable modem and I am back up to 700Mbps. I monitored the network to make sure that there wasn't some device that was hogging my bandwidth, I didn't see any culprits. I also cleared the log on the cable modem so I can see any new error messages coming in over the last couple of days and nothing jumps out as a problem, I did see this warning:

I have found a bunch of other posts with people with similar issues, but nothing that really matches. A lot of people report their modem disconnects completly, which isn't the case here. I was thinking of buying a new cable modem, but this one is only 1.5 years old and shouldn't want to make sure that it is the modem before spending $ on a new one.