I have no idea what happens as I can't see any errors in console, but it breaks down somehwere, I guess, in this part:

if (!tailwindTypographyClasses.every(
  (className) => classList.contains(className)
)) {
  classList.add(...tailwindTypographyClasses);
}

As the classes are not applied to the .wp-block-post-content element.

Working fine in wordpress version 6.2.2., not working with 6.3.

Sorry that I am unable to better pinpoint where it breaks or suggest any fixes.