If stereo pairing is not possible while connected to the AUX plug on the speaker, you may need to use custom cables coming out from the TV to each speaker. The tip/ring/sleeve of the standard headphone jack supports two audio channels and you’d need to create one somehow to be sure the left audio channel goes to one speaker while the right goes to another speaker.
The tip/ring/sleeve (use the middle image below) refers to the three separate conductors on the headphone/AUX connector that plugs into the speaker, “tip” (or left channel positive) being the end conductor, “ring” (or right channel positive) being the second from the tip and “sleeve” (or negative/ground) being the longest conductor.
Like I said above, this would likely require one to build custom cables since I could find nothing remotely capable of doing this like at Amazon or Monoprice(.com). Building cables like this is very doable (I’ve done many, many custom cable builds similar to this) but you’d need access to the parts (cables, connectors) and have the ability to solder and follow simple wiring logic.