Yes, it works properly in the editor and when I play the project with the camera with the script in the editor. Just when I built and try running the built project and get to the unity watermark afterwards it does this bug. I'm not using URP (I checked just now).
https://drive.google.com/file/d/16tU_WJbNLCHJ8NiP1uGV3RA-jXnjSULf/view?usp=shari...
If it works for you, you should see a red sphere in the middle with the whole camera having the JPGPU filter.
If it doesn't (like on my PC) it will seemingly freeze after the unity logo.
Another thing to note is that your demo of JPGPU ( https://ompuco.itch.io/hlwl ) works fine when I test it out in my web browser.