What kind of display do you have? Are you COMPONENT or HDMI (or composite?)
I experienced the same (If not a very similar issue): See if this matches:
On my LG Panel, I can set the aspect to 16:9 MANUALLY and it works fine. Ordinarily, I have it set to “Set by Source”, and when I do, it behaves like this:
If I config’d the player as Widescreen, Netflix 4:3 content shows up as 1:1 (Yes, it’s SQUARE.) Netflix 16:9 content shows up as 4:3. ICK!
If I confg the Plus as “Normal” screen, then Netflix shows 4:3 content just fine (it’s Pillarboxed) and 16:9 is both Pillar and Letterboxed, but at least the aspect is correct.
So, all of my panels have the ability to set the aspect ratio specifically (on Component inputs), you don’t actually want to STRETCH. After setting mine to 16:9 MANUALLY, I have had no reason to change it to anything else.