I am no expert with AWS but I once had a similar issue in which the following URL helped me. https://repost.aws/questions/QURxK3sj5URbCQ8U2REZt7ow/images-not-showing-in-angular-application-on-amplify
We did move our images in S3 but the solution of modifying amplify.yml seems a possible way to fix your issue.
Hope this helps fix your issue.