I also have sent this to my contact at DLink. So they are aware of it. It would be interesting to see if there was an issue between the DLink router and the ISP modem. Ya, the ISP modem might not exhibit this however that could be a false positive and the connection between the these Arris modems and DLink routers could have some sort of incompatibility. If you or anyone else can take this model router to a family, friend or neighbors place that doesn't have an Arris modem and run a quick test to see if this router works or if the problem follows there, would be helpful to know this. I'm sure DLink is working to review this issue.
Thank you for your feed back.