When the request body type is set to Form-data and you add multiple parameters with the same key, Bubble only sends the last (bottommost) instance of that key. Bubble's current setup stores key/value parameters as objects rather than arrays, which means duplicated keys aren't preserved. Tools like Postman support sending multiple values under the same key, but Bubble doesn't expose this.
What you might notice
When you have duplicate parameter keys in a Form-data request body, only the last key/value pair is sent
In tools like Postman, both duplicate keys are sent correctly
Workaround
Switch the body type to "Raw" if you need to send multiple values with the same key.