From we previous discuss, the issue relates the
RequestFilter. You can try to remove it.
Then, to read the request body in the action method, we should not use the
[FromBody] attribute and parameters. Because the request body can only be read once, from beginning to end. So, after model binding, if we still using the StreamReader to reader the request body, it will return empty.
So, you can refer to the following code to read the request body in the action method:
More detail information about the HttpContext, see Use HttpContext in ASP.NET Core (#Enable request body buffering).
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