Arris SB6182 issue operating at 10/100

I recently solved an issue with the Arris SB6182 that I wanted to report here, either to find out if I may have a bad modem or to report something you may want to add to your internal knowledge base. After registering the SB6182 I was having a slow speeds issue that took a few hours to TS and resolve. My hardwired download speed tests were coming in at around 20 Mbps, sometimes spiking up as high as 35 Mbps. My upload speeds were fine. I was initially on your 100 Mbps speed package, which I had your CS lower to 50 Mbps during troubleshooting. Regardless of my provisioning, I was only getting 20 Mbps (with the occasional spike to 35) through my router. I am using a TP LINK TL-R470T+ with the latest firmware as my router. This is a multi-WAN load balancing router that I use in conjunction with CenturyLink DSL as a backup in case either connection goes down (I do WAH tech support and can't afford to miss work). The router unfortunately only operates at 10/100. The CLNK modem was not connected and not a factor during my troubleshooting. Initially your T2 tech support blamed my router, since speeds were fine when my computer was hard wired, and at first I agreed with them. On a hunch though, I decided to put a Netgear gigabit switch between the modem and the router, and my speeds were finally correct. On the 50 Mbps provisioning I was seeing around 60+ Mbps. It seems as though the SB6182 has a speed issue when the gigabit port is operating in 10/100 mode. Buffering the connection to my router with a gigabit switch allows the modem's port to transmit at gigabit speeds and resolves the issue. I poked around in the SB6182's firmware to see if I could adjust the speed of the port manually to 10/100 to no avail. I wasn't really using the switch for anything so I don't mind leaving it in place, but I'm wondering if this is a known issue or if there is a firmware update to correct; I assume I have the latest firmware. If you think I should exchange the modem, let me know. Either way, you guys might find this info helpful when TS'ing slow speed issues on this modem with other customers.