Lightroom Classic adds the green border to HEIC files from iPhone. See the original photo and a screenshot. If I edit this image in Photoshop (after applying the Lightroom corrections), I can see and edit the green border there as well.
P.S. The files are modified because of this stupid limitations:
Sorry! We were unable to upload your image because it was over 2MB in size. Please try uploading a smaller version of the image.
Sorry! We were unable to upload your image because it is not a PNG, JPG, or GIF file. Please ensure your image is one of these formats and try again.