πŸ’ͺπŸ’ͺπŸ’ͺ YESSSS! I finally SOLVED IT, after f**king Day 4! I knew it wasn't anything to do with my Rails API or the strong params, but that kept distracting me because that's the error I can see from my Rails console, not the error that's from the bug. In the end, it was how the input fields in my Vue app were structured that kept sending malformed json to my Rails endpoint - creating a proper input form helped. Also reading the npm axios docs and understanding the request configs helped lots! I ended up answering my very first question on Stack O. Do I get more points for that? 🀣πŸ€ͺ https://stackoverflow.com/questions/63986178/400-bad-request-issue-with-post-request-from-my-vue-app-to-my-rails-api/64010015