This one can really annoy folk. You'll find the same issues with other makers so let's just nod and if the product isn't performing, why keep it?
No, I know of no maker that considers this a bug.
I own a 47LA691S LG SMART TV. When I'm watching a movie by USB, everything is normal (audio languages, subs, etc). When I watch the same movie over an ethernet connected disk, I can't change audio languages, subs and all options are disabled on menu lists.
I connected the ethernet cable directly from the disk to TV, no responce. I also bought an ethernet-to-usb adaptor trying to resolve this, but still nothing.