I just tested it on a live site with PHP 8.1 and it was fine. It could well be a Flywheel issue. The images I was uploading were approx 1Mb and 2560px in width. I never upload images above the WordPress max. I did multiple images so I really don’t think that is the issue. What is interesting is disabling the plugin solved the issue, I was able to upload the images. So there is some conflict with Local by Flywheel when it is on PHP 8+.