Live TV on 16GB NVidia Shield TV

Like many people have discovered, watching Live TV on the 16GB Shield TV often results in the “weak signal” error. On the page below it suggests “changing the transcoding folder to a faster attached drive” - my question is how?
https://support.plex.tv/hc/en-us/articles/221099648

I have increased the internal storage to 64GB with a Sandisk Extreme Go. I still get the “weak signal” error while watching Live TV. I have also gone into Settings > Server > Transcoder and changed the “Transcoder temporary directory” to:
/sdcard/TV Shows

Still no luck. What am I doing wrong?

I have read through this thread, but there’s still no direct step-by-step instruction what we need to do: