Audio issue with VMS1100; sound only works when cycling TV input?

[binarymango]

We've had FiOS for many years. Just got upgraded to "FiOS One" and the new VMS1100 box. Hooked it up to our Vizio TV just like we had the old FiOS box hooked-up (via HDMI cable). Video works fine, but for some reason the audio from the FiOS box will only work if we switch the input on the TV (HDMI1, HDMI2, HDMI3, etc) away from the FiOS box and then *switch back* to the FiOS box! In other words, if we have the HDMI1 input selected (which is where FiOS box is connected) and we power-down the TV, then turn the TV back on.... video will work but there will be no sound. If we then switch to another input then switch back to HDMI1, the sound works. Any idea what could possibly be causing this? Our previous FiOS box did not behave like this.

Other things I've done:

- Tried different HDMI inputs on the TV, same result

- Tried different HDMI cords, same result

- Tried switching audio setting within the FiOS box from "Surround" to "Stereo" but same result

- We use a Vizio soundbar for audio, but it makes no difference whether it's the soundbar or the built-in TV speakers... same phenomenon is happening where there is no audio coming from VMS1100 to TV until we switch HDMI input and then switch back to box

Thanks in advance for any help!

[CRobGauth]

Is connection passing through the Vizio to TV or direct to TV and then to soundbar (invariably via optical out)?

If doing pass through, I know Verizon has had some issues in the past.

Using optical out can allow multiple connections to TV to always use the soundbar.

[binarymango]

Thanks for the reply!

The FiOS box is connected to the TV via HDMI, and then the soundbar is connected to the TV via optical. So the FiOS box's audio connection is passing through the TV. Could you clarify the issues that Verizon was having in the past? Anything that can be done? Is it faulty hardware or something else?

Thanks again.

[CRobGauth · Accepted solution]

There were handshake issues when passing through sound bar to TV. Was software issue. Don't remember if it was the vms1100 or previous stb. No reports on the vms4100 I have seen. Do you have more than 1 stb? If so, have you swapped them around?

[binarymango]

Thanks for the suggestion! Going to try swapping boxes to see if we get the same result.