Hello :D … i believe, that the problem is just a misinterpretation of the Adobe Premiere Pro.
It’s happen to me, on videos captured by OBS Classic (v0.659b). The Pixel Aspect Ratio shows (0.75) instead of (1.0) on Adobe Premiere Pro. Below is my solution ;)
The Problem:
Video clip that in Adobe Premiere Pro shows the properties, ex: [Movie, 1280x720 (0.75)] instead of [Movie, 1280x720 (1.0)]
The Solution:
Note: All the process is done in Adobe Premiere Pro
1 - Load the video into the "Project" window
2 - Right-Click on the video and choose (Interpret Footage)
3 - On the (Pixel Aspect Ratio) tab, choose [Conform to = Square Pixels (1.0)] and click "OK"
4 – Done
Good day to everyone :D