Travis Listak said about 2 years ago on Cropping Active Storage Uploads :
If you are using Rails 7.0.1 with cssbundler bootstrap:

in javascript/controllers/cropper_controller.js
do not use this line `import "cropperjs/dist/cropper.css"`, it will break when you run `yarn build:css` by overwriting your `app/assets/builds/application.css`

Instead:
1. Copy cropper.css from `./node_modules/cropperjs/dist/cropper.css`
2. Paste it into `app/assets/stylesheets/cropper.scss` notice the extension change to scss
3. In `app/assets/stylesheets/application.bootstrap.scss` add `@import cropper;`
4. Run `yarn build:css` and whatever javascript bundler you are using. Everything should work correctly.