Not sure I understand what ‘as ants’ means, but as to the optical not working, the source you were watching was likely of a greater bandwidth than can be handled by optical, or even some folks have missed taking the ‘caps’ off the optical cables. If you locked down the source to Dolby Digital only, and made sure the optical port was on in the TV’s settings, it probably would have worked.

I’ve never found a Best Buy associate who knows as much as I do about connections, and I’m by no means any sort of expert, just mildly experienced…which you should read as I’ve learned from making my mistakes. Best Buy folks are well intentioned, usually, just not well trained, or knowledgeable, at least in my experience. 

Since there is no financial relationship between Sonos and LG, I’m not sure I understand your disappointment in both companies. Based on my interpretation of your post, you might want to direct your ire at Best Buy, for incomplete knowledge of the technology they are selling to you. 

There is no reason for optical not working, unless you left the caps on the ends of the cable, or have not configured your TV to send its audio via optical.

Ranting at companies isn’t helpful when the RCA is in fact the user.