Xfinity Wifi Extender Pods - Ethernet performance WORSE than Wireless

Hi.

For the first time in many years, I'm using Xfinity gear for my home modem & wireless access points.  This includes an XB8 integrated cable modem & two XFi extender pods.

The Xfi extender pods seemed a necessity as I was getting poor streaming performance for some devices in parts of the household where I presume I was not getting good wireless signal.  On balance, wireless performance has been better since installation of the pods.

However, the performance of devices connected to the XFi pod ethernet ports is AWFUL. 

Which is to say it's significantly worse than the wireless performance of the same devices, where I'm able to compare, when not connected via ethernet.   That should NEVER be the case.  I'll provide a specific example from this morning:  Using Xfinity's speed test site, I got 48-50Mbps download speeds from my PC while connected via the ethernet port.  Disabling the port and enabling WiFi, I got 335-350Mbps download speeds from the same device.  I ran the test twice in each configuration to make sure the results weren't one-off flukes.

Additionally, devices connected to the ethernet port take FOREVER to reconnect in the event of a sleep/hibernate/power down state.  I've never had this issue with any other ethernet devices.  On Windows devices I usually disable the ethernet interface entirely and then re-enable it in an attempt to speed up this incredibly slow process that can take several minutes.   The expected behavior is that when devices awake from sleep they're able to re-establish data layer link and renew their IP leases within a few seconds at most and return to the network - not sit disconnected for minutes at a time because the upstream XFi Pod isn't responding to client requests to re-establish link.

And the poor performance of the ethernet ports is not just some academic issue - I have a NAS that requires an ethernet port.  All my file transfers to and from the NAS are incredibly slow, and it now seems likely that this is because it's connected to the ethernet port on an extender Pod.

My question to Xfinity:  Why is wired ethernet performance SO BAD?  It should be at least as fast as the speed of the wireless connection from the extender pod to the XB8, which appears to support at least 350Mbps in the case of my testing - but the wireless connection was 7 times faster than the ethernet connection to the pod.

Referencing XFinity's own statements on the matter:  "Hardwiring your device to a Pod would give you slightly faster speeds than connecting the device to the network over WiFi."  Yes, that should be true, but it's not the case here.

‎Plug Pod into Ethernet LAN Switch? | Xfinity Community Forum

Looking forward to hearing back from XFinity with some constructive feedback on how to improve the link & speed performance of my ethernet connections to XFi Pods.