Xi6 TV Box is constantly stuttering, locking up, losing connection, buffering, …

Last Dec 2025, after power outage due to storm TV Box was replaced with a new out of the box Xi6 TV Box.  Worked OK when tech was here.  After he left, we found out that the “rewind feature” did not work (let’s you got back 60 minutes in program history).  As time as progressed, buffering, stuttering, etc have really been an issue.

Called xfinity on phone several times and then went to xfinity store (guy there said “just like an auto sales person doesn’t fix cars, he just sells Xfinity products and has no idea how to solve problems”.  So, for well over a month I have been fighting the Xi6.

Issues are: while watching a show - it just pauses and then may go to black screen or to a different channel, or drop the rewind feature and go to live TV, lock up to black screen or …….   Errors codes that have popped up are RDK-03117 and XRE-03090.

Equipment is an owner modem (XFINITY APPROVED) going to a Synology 2600 router.  We have gig internet service.  I have rebooted the TV box and modem and router more times than I can count. Nothing has helped.

The house is on a MESH wifi network and signal is listed as EXCELLENT by the Xi6.  iPads in the room work without any issues.  WIFI speed tests show 150-220 mbps in the room.  On router, IP address of TV Box is assigned and fixed, device listed as HIGH priority.  A ROKU stick on the same network and placed within 1 foot of the Xi6 TV box streams xfinity programming WITHOUT ANY ISSUES.  I even tried using an Ethernet connection to the Xi6 TV box to eliminate any questions about wifi.  I had all the same issues with an Ethernet connection to the Xi6, so our wifi is not the issue.

So far, XFINITY in person and on the phone have been USELESS.

Based upon the wifi signal strength, performance of the iPads and ROKU stick, and router priority settings, the issue should not be related to MY wifi/internet system.

Any one have similar experiences and HOPEFULLY A SOLUTION!