Thanks for the update, there is something going on with the videos themselves.
I uploaded one of your mp4's into a page and had the same issue. The dimensions 576 × 720 are cropped to a 1080 x 720 aspect ratio , the cropping to landscape occurs.
Then i added a random portrait video to see if it was a Lay Theme BUG, portrait dimensions are maintained:
Then i wondered if the video falls under a certain "portrait" dimension does it get changed to Landscape? Like your video, if its portrait but not true portrait and somewhere in the middle is that causing the issue? Turns out no. I used an online video resizer to change the dimensions to the exact same as yours to test - 576 × 720 :
You can see the video is given the correct dimensions.
Even though your Beastwang videos look Portrait, the Media Library believes the dimensions are 1080 x 720 ( even in my Lay Theme, so it's not a lay theme bug then ).
If i change the dimensions of your video in a simple video resizer to the correct 576 x 720 - The Media library now sees this correctly and it is maintained on the front-end:
Within your videos are some encoding, unsure what exactly that is giving this 1080 x 720 aspect ratio, resizing the video's solves the issue or look into how the video's where exported from whatever programs you are using (taken directly from instagram?).
Hope this helps Jacob and best wishes for 2022! 🌝