Riffing off Roadkill Smorgasbord:

Berm Jerky

There is no finer band name than: Ümlaut and the Fish Mongers.

Track down the workorder for the sign installation via FOIA?

Look for security cam footage? (Quickly in case it rolls over.)

Tough thing to prove.

I'm sure your congresscritter will have a solution for you.

In the meantime, were you watching over-the-air, with an antenna direct into your TV's tuner? Over cable, thru a set-top box? Via satellite, like DirecTV? Over the internet, like YouTube TV or other streaming supplier?

Your experience points to an audio channel misconfiguration somewhere in the chain. And that path can be pretty convoluted the more cooks there are in the kitchen.

At first glance, it looks like a 5.1 conversion issue as others have stated. Your set is configured for/expecting 5.1, but the speakers are set to be the center channel in an external 5.1 system... but the rest of that system doesn't exist. This could be a TV fault, or incorrect 'metadata' coming from the broadcast or any of the above re-broadcasters or set-top box. The spots aren't encoded as 5.1 so they come thru fine.

It's unlikely to be a full-on conspiracy, though.

We often called it a tag ending in the recording studio, but I don't know how 'official' that is.