Visitor

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2 Messages

Thursday, May 14th, 2026 8:11 PM

Xfinity TV wifi adapter design problem leads to drifting audio/visual sync

The Xfinity TV wifi adapter design has a problem leads to drifting audio/visual sync. In particular with a noisy RF environment such as apartment or condo buildings. It appears that the audio is carried over a TCP based protocol while the video is carried over a UDP based protocol. The problem is that with a high frame error environment, the audio will be retransmitted when errors happen, leading to an ever-increasing audio/visual delay as the video is not retransmitted. After a power-on restart, viewing TV through the xfinity wifi adapter is fine, but over several hours the audio drifts to a longer and longer lag, sometimes reaching a full second. I fix it by cycling power on the wifi adapter, which is very annoying. You need to fix the firmware in the xfinity wifi adapter to use a fully UDP based protocol such as RTP or RTSP to keep audio/visual synchronized.

When using the smart TV's (Sony) built-in wifi, so it is exactly the same wifi radio environment, the TV's streaming apps like Netflix or AppleTV do not lose sync at all. It is strictly a problem with the Xfinity wifi adapter box, where regular "cable" TV has ever-increasing audio lag and even Netflix over the xfinity wifi adapter also has ever-increasing audio lag.

This really needs to be fixed. I do not like having to power cycle the Xfinity wifi adapter once or more daily.

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Official Employee

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175 Messages

22 days ago

Hello @user_e7t51a, and thank you for posting our Xfinity Forum providing this detailed write-up.❤️ We completely understand how frustrating it is to have audio gradually drift out of sync, especially when a power cycle becomes the only temporary fix. This is not the experience we want our customers to have.

While we’re not able to confirm protocol-level details here, we do want to help with troubleshooting and make sure your feedback is shared with the appropriate team.

To help narrow this down, could you share a few details? 

- Which device model are you using (for example: Xi6, XiOne, or Xi5), and is it connected wirelessly or via Ethernet?

- Do you notice the sync drift on live TV only, or also within apps like Netflix on that same box?

- About how long does it take before the delay becomes noticeable?

- What is your audio setup (TV speakers vs. soundbar/receiver), and have you tried another HDMI cable or port?

Here is some information that may help improve your experience: 

- If possible, try connecting our box via Ethernet to see if the drift continues. Wireless TV Boxes support a wired connection, which can help rule out WiFi interference. 

- Make sure the box is positioned where it maintains a strong, consistent connection to your gateway. 


You can more information about troubleshooting audio from our helpful article https://www.xfinity.com/support/articles/troubleshooting-audio-issues-with-xfinity-tv

and for more information about our Wireless TV Box setup and requirements, see: https://www.xfinity.com/support/articles/wireless-tv-box-faqs

Please give these steps a try and let us know how it goes. If the issue continues, we’ll be happy to take a closer look with you.

Visitor

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2 Messages

I have this problem with my current xfinity tv wifi adapter, and had it at a prior house with a different physical xfinity wifi adapter. It is not a hardware problem. The issue occurs with great frequency now (cycle power at least daily) because the wifi environment here is very crowded, a high frame error environment. Let your engineers know to test in a high error environment. I know, I am a communication systems engineer and have designed systems like this that work properly.

My setup consists of a recent Sony smart TV, an xfinity wifi adapter, and an xfinity XB7 access point. The wifi adapter is located approximately 25 feet from the access point. My wifi connects at 5 GHz, all XB7 access settings other than ssid and password are xfinity defaults.

Running a wifi analyzer on a pc, located close to the tv, I can see 50 networks, several are stronger, even a full 10 dB stronger, than my own network.

When I use my Sony TV's built-in wifi adapter and its streaming apps, audio and video sync are fine.

With the xfinity wifi adapter the audio and video start in sync but over the course of a few hours they drift apart, extremely annoying when it develops to a full second audio delay.

Official Employee

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175 Messages

@user_e7t51a, thank you for the additional details. We'll be happy to take a closer look. Please send us a direct chat message with your full name and complete service address to "Xfinity Support",  so we can securely access your account and assist further. To do so, click on the chat icon located at the top right of this forum's page.
Here are the detailed steps to direct message us:
Click "Sign In" if necessary
Click the "Direct Message” icon (upper right corner of this page)
Click the "New message" (pencil and paper) icon
Type "Xfinity Support" in the "to" line and select "Xfinity Support" from the drop-down list
Type your message in the text area near the bottom of the window
Press Enter to send your message

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