▂▅▇█▓▒░('ω')░▒▓█▇▅▂うわあああああああ 原因 jQuery API Documentation を見ると、 It is converted to a query string, if not already a string. It's appended to the url for GET-requests. See processData option to prevent this automatic processing. Object must be Key/Value pairs. If value is an Array, jQuery serializes multiple values with same key based on the value of the traditional setting (described below). と書いてあり
![$.ajax でオブジェクトの配列を POST したい - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/93deba9e613b73d976b3d63e3aade1f1e9bde375/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-9f5428127621718a910c8b63951390ad.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTkxNiZoPTMzNiZ0eHQ9JTI0LmFqYXglMjAlRTMlODElQTclRTMlODIlQUElRTMlODMlOTYlRTMlODIlQjglRTMlODIlQTclRTMlODIlQUYlRTMlODMlODglRTMlODElQUUlRTklODUlOEQlRTUlODglOTclRTMlODIlOTIlMjBQT1NUJTIwJUUzJTgxJTk3JUUzJTgxJTlGJUUzJTgxJTg0JnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9NTYmdHh0LWNsaXA9ZWxsaXBzaXMmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz1kOWNhNjA2NzBlNTU4NDExMGJlNmNhYjZhMTBhNzIxMQ%26mark-x%3D142%26mark-y%3D112%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTYxNiZ0eHQ9JTQwUVVBTk9OJnR4dC1jb2xvcj0lMjMyMTIxMjEmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9MzYmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz1jYzMxZDlhZTA4MDExNThlYWI2Y2U0ZjViMzhkNDc4NQ%26blend-x%3D142%26blend-y%3D491%26blend-mode%3Dnormal%26s%3D9d6f8e538052a1f2e09a278147c91c7f)