Problem requesting data based on URL parameters in React-Redux - node.js

Question

On a MERN-stack application, I would like to request data from a particular user's schema based on the url parameters. For instance, http://localhost:3000/user/User1 would render data from User 1. I am using redux-react for state management. Here is what I currently have, and here is what's happening.
Userpage Component
import React, { Component } from "react";
import {getUser} from '../../actions/userActions';
import {connect} from 'react-redux'
class Userpage extends Component {
componentDidMount() {
getUser(this.props.match.params.username)
}
render() {
return (
<div>
<h1>Hello</h1>
<h3>{this.props.user.name}</h3>
<h3>{this.props.user.email}</h3>
</div>
);
}
}
const mapStatetoProps = state => {
return{user: state.user}
};
export default connect(mapStatetoProps, getUser) (Userpage)
userActions
import axios from 'axios';
import {GET_USER} from './types';
export const getUser = username => dispatch => {
axios
.get(`/api/users/${username}`)
.then(({res}) =>
dispatch({
type: GET_USER,
payload: username
})
)
};
userReducer
import { GET_USER } from "../actions/types";
const initialState = {
user: {},
};
export default function(state = initialState, action) {
switch (action.type) {
case GET_USER:
return{
...state,
user: action.payload,
}
}
Then in the api/users route, I have the following:
router.get("/:username", (req, res) => {
User.findOne({username: req.params.username})
.then(user => res.json(user))
});
Beyond the user state returning as empty, here are some errors I am getting.
On the command line, I occasionally get a
Could not proxy request /api/users/function%20(action)%20%7B%20%20%20%20%20%20%20%20if%20(typeof%20action%20===%20'function')%20%7B%20%20%20%20%20%20%20%20%20%20return%20action(dispatch,%20getState,%20extraArgument);%20%20%20%20%20%20%20%20%7D%20%20%20%20%20%20%20%20return%20next(action);%20%20%20%20%20%20%7D from localhost:3000 to http://localhost:5000.
As well as a
mapDispatchToProps() in Connect(Userpage) must return a plain object. Instead received undefined.
Any help or guidance would be greatly appreciated.