You are absolutely right, you didn't plagiarize and you are in fact the author. Thanks for verifying this fact with us by posting a link back to this post from reedsy: https://blog.reedsy.com/short-story/d7hn1c/#comments

We are sorry for accusing you of plagiarism. As for the rule about not reposting previous work, what's done is done, but now that you know the rule, hopefully, hivewatchers will be lenient this time and you can use this as a learning experience.