Recurring "No Signal" on cold boot with Vizio 4K TV & Xfinity XG1v4 (HDMI Handshake)

Hi everyone,

Looking for insight on a persistent "No Signal" issue occurring after the TV and cable box sit turned off or idle overnight.

The Setup:

 TV: New Vizio 65" 4K Smart TV (Model VQM65C-1004)

 Cable Box: Xfinity X1 4K DVR (Arris XG1v4-A)

 Remote: XR15v2-UQ

 Cable: High-speed HDMI routed in-wall (approx. 16 years old)

The Issue:

Almost every evening or morning upon turning on the TV, the screen displays ⁠"No Signal - Xfinity X1"⁠. The Vizio recognizes the device name on the port, but no active video stream appears. Pressing power on/off on the remote does not fix it; the only reliable fix so far has been physically pulling the power cord on the X1 box to force a hard reboot.

Troubleshooting Already Completed:

1. Replaced Hardware: Swapped both the X1 DVR box (got a fresh XG1v4-A) and the XR15 remote. The TV itself is brand new.

2. X1 Box Power Settings: Verified Power Saver is OFF.

3. Vizio Power Settings: Confirmed TV is set to Quick Start mode (not Eco Mode).

4. Output Resolution: Fixed the X1 output resolution settings rather than leaving it on auto-detect.

5. Adjusted HDMI Port & CEC Settings: Disabled CEC Device Control on the Vizio and changed the HDMI Port Mode from Auto/Standard to Compatibility (Legacy HDMI) to accommodate the in-wall cable bandwidth.

Since all three primary devices (TV, cable box, remote) have been replaced, this seems to be a cold-boot HDMI handshake/EDID timing issue—likely triggered when the X1 box runs overnight background updates.

Has anyone with a similar Vizio + X1 setup resolved this without having to manually power-cycle the cable box daily or re-fish an in-wall HDMI cable? Any specific handshake/CEC tweaks that worked for you?

Thanks for any help!