intermittent internet connection

In the evenings, my internet frequently, randomly disconnects for short periods.  I notice that the # of uncorrectable is about 30% of the correctable. I currently use a new SB6183 cable modem, Apple Airport extreme base & Apple Airport Express in bridge mode.  

I've taken the following actions:

1. Relocated both routers to improve signal in major use areas (all devices report Excellent quality with RSSI better than -67 dBm)

2. Hardwired Apple TV to reduce demand on my internal WiFi

3. Reviewed router channel assignments and moved to least congested/ lowest noise.

4. Purchased SB6183.

5. Reviewed modem setup with Arris...very helpful.

6. Reviewed router setup with Apple...very helpful.

Talked several times with cox over the past few months who made some changes at the curb and in my house.

Any suggestions on what I can do to get rid of the nuisance disconnects?

Current modem report as follows: