Axios post data shows in config, but not data, no body passed

Question

I have a react frontend sending to a mongoose/express backend. Previously I was using flask for the backend and everything ran fine, this issue only started after switching to express. On postman, the call goes through perfect, but when I try through the browser, I get a 200 response, with an empty document created. In the console, the correct data shows in the config object, but not in the actual data object.

Heres the React/Formik onSubmit sending the post:

onSubmit={async (values) => {

      console.log(values);
                 
      const headers = {
        'Content-Type': 'application/json,multipart/form-data'
      };  

     await axios.post('http://localhost:5000/api/clients', values, {headers})      
      .then(response => {
        console.log(response);
        return response;
      })
      //.then(this.props.history.push('/Clients'))
      .catch(function (error){
        console.log(error);
      });
      
      
    }}>

Heres the console response (the first object is the console.log(response) from the onSubmit):

Object { firstName: "Johnny", lastName: "Cochrane", phone: "8585678899", id: "" }
​
firstName: "Johnny"
​
id: ""
​
lastName: "Cochrane"
​
phone: "8585678899"
​
<prototype>: Object { … }
AddClient.js:49
Object { data: {…}, status: 200, statusText: "OK", headers: {…}, config: {…}, request: XMLHttpRequest }
​
config: Object { url: "http://localhost:5000/api/clients", method: "post", data: "{\"firstName\":\"Johnny\",\"lastName\":\"Cochrane\",\"phone\":\"8585678899\",\"id\":\"\"}", … }
​
data: Object { _id: "62043b723fe12d6b4ec354b8", clientId: 12, __v: 0, … }
​
headers: Object { "content-length": "71", "content-type": "application/json; charset=utf-8" }
​
request: XMLHttpRequest { readyState: 4, timeout: 0, withCredentials: false, … }
​
status: 200
​
statusText: "OK"

Any help would be greatly appreciated as I'm at a total loss. Thanks