Just a heads up as these boxes are becoming standard. I have quite a few clients that either had a forced upgrade or new install and most of them had a significant audio delay on Fios, be it Sonos, soundbar or AVR. After spending hours between jobs pulling my hair out I finally figured out the fix. This is a known issue with these boxes, yet Verizon refuses to fix them. Out of desperation I dug into the secret menu of them and found the fix!

Press the power button on the remote once and the ok button twice in (rapid succession) -This will bring up the menu (white and generic)

press the LEFT button on the arrow pad.

This brings up selection of 4 options

Select USER settings

Select HDMI Settings

Select HDMI Audio

Use the keypad and select L-PCM, press OK then back out, this fixes the delay!

It cannot be set to auto. Don't bother adjusting the delays in your receivers or TV's because the delay will follow the other devices (game consoles, streaming devices, etc)

Just did that on 2 X Cox boxes yesterday. This client only had a delay on one channel but the old PCM trick saved the day!

But do you still get multi-channel audio?

A lot of cable boxes (and other devices) will only give you 2.0 if you select LPCM. In order to get multi-channel audio thru LPCM connection, the source unit has to have decoders. Which adds to the cost of the unit. That's a big reason why you only get 2.0 from most cable boxes and other cheap boxes, using LPCM.

If your customer has a surround sound system and you are only getting 2.0 now from the cable box - that is NOT a fix. It is just swapping one problem for another.

In before “I put my surround systems in all channel stereo anyway”.

no amount of education can make some customers understand that surround sound doesn't mean all the shit comes out of all the speakers.

I've given up on life and don't even bother arguing when they want the system set up this way.

I'm likely to go the four channel stereo route later today for a customer who has been constantly complaining about "poor surround".