Axios and TypeError: "cyclic object value"

Question

I keep getting the error in the title and cant figure out why.

I have painful quest to generate multiple (5-10) pdf files at once, and send all of them to my server.

when i click button, it will trigger this for loop which generates rows and colums as arrays. To be send to jsPDF

  uploadMultipleContracts = (e) => {

    let pdf = []
    const columns = [
        { title: 'Date', dataKey: 'date' },
        { title: 'User', dataKey: 'user' },
         ....
    ]

    const rows = []
    for (let i = 0; i < this.state.multipleDetailContract.length; i += 1) {
            rows.push({
                date: this.state.multipleDetailContract[i].date,
                user: this.state.multipleDetailContract[i].user,
                ....
            })

        if(e.target.name === "save"){
            pdf.push(this.sendMultiPDF(columns, rows));
        }
    }

    console.log(pdf)
    this.pdfSender(pdf)

};

Then we push return value (pdf file from this.sendMultiPDF(columns, rows)) into array of pdf's let pdf = [] after this the console.log() will print array of chosen PDF files, it looks just as you would expect, 5-10 objects in array, all look like proper PDF.

then we send this array set to this.pdfSender(pdf) which has axios in it

pdfSender = (data) => {
    axios.post(`${process.env.API_URL + process.env.API_PORT}api/test`,
        data,
        {
            responseType: 'arraybuffer',
            headers: {
                'Content-Type': 'application/json',
                'Accept': 'application/pdf'
            }
        })
        .then(function () {
            console.log('SUCCESS!!');
        })
        .catch(function (error) {
            console.log(error);
        })
};

but pdfSender will catch and throw error TypeError: "cyclic object value"

All google did provide is some explanation of object refering to itself. I dont know, or cant figure how that would be the case.

multipleDetailContract:

{
 "contractid" : "xxxx",
 "user" : "xxxxxx",
 "date" : 12-03-18,
 "hasUpperLimit" : "true",
 "alert" : null,
 "fees" : yyyyy
}