If after trying what TomH309 suggests the problem persists, some possibilities exist.
One common problem is Dolby Digital. Try multiple channels. Some channels use Dolby Digital and others don't, but some Tv's do not support DD. I believe the Verizon Boxes default to DD if present (or it may have been set so by instaler). For Tv's that do support DD you need to set to linear pcm. Setting it is often in some hidden menues.
Arris Quantum boxes. Turn on, hold d about 5 seconds and release, user settings, additional hdmi settings, audio output, left or right to l-pcm
Older ARRIS (formerly Motorola) box. From on, turn off at box, then hit ok, and then menu on remote (somewhat time sensitive). The rest is similar to above, but I don't have a box to check on at my FL home.