Issue with Export Frame squeezing image

I have a nested sequence that is 4:3 ratio that, when I use the "Export Frame" option produces an image that is squeezed. When I open it in Photoshop, a dialog box pops up reading "Pixel aspect ratio correction is for preview purposes only. Turn it off for maximum image quality."

So, I guess Premiere is exporting images with pixel aspect ratio issues? How can I fix my image?

Nested sequence settings here:

Exported frame: