stream error: Handler dropped payload before reading EOF in Actix Rust

Question

I have an app using Next.js (^12.0.10) and Actix (4.0.0-beta.10) in the Server. I want to send images, transformed into base64 format, to the server then decoded back to binary and to save them in the server.
Everything works fine when I send pictures less than 2MB approx, since even if the image is a few hundreds of bytes the base64 conversion increases the value a lot. If I send an image greater than that I get the following error:

[Error ] handler did not read whole payload and dispatcher could not drain read buf;
    return 500 and close connection
[Error] stream error: Handler dropped payload before reading EOF

In the rust server I made the next changes, since I thought it was a problem with the payload:

HttpServer::new(|| {
    App::new().app_data(web::PayloadConfig::new(50_242_880))
})
...

And in the client using axios (^0.24.0):

class NewUniversity {
    name: string;
    img_file: string;
    img_type: string;

    constructor(name: string, img_file: string, img_type: string ) {
        this.name = name;
        this.img_file = img_file;
        this.img_type = img_type; 
    }
}

async function addUniversity(data: NewUniversity): Promise<AxiosResponse<string>>{
    const url = `${backendsrc}/university`;
    // Default options are marked with *
    return axios.post(url,data, {
        maxBodyLength: 50_242_880 // 50MiB
    });
}

Still after those changes I keep receiving the same error. Do I need to send the base64 data from the images compressed and then have it decompressed in the server? or is there another method?