Correcting for Unity Lens Distortion in OpenCV

I'm working on a project for stereo image construction using OpenCV and frames of a video from multiple angles in Unity. I have noticed that there seems to be significant radial distortion when I attempt to triangulate points in the images with OpenCV.

So I was wondering if anyone here had any insight on why that may be happening? The issue persists despite learning the distortion coefficients with my camera calibration as well as significantly increasing the size of my calibration data. I don't know if this is an issue reflective of Unity adding in it's own radial distortion somewhere or OpenCV simply not performing adequately.

Thanks.