ReactJS Bootstrap Navbar and Routing not working together

First of all, in your snippets it doesn’t seem like you’re wrapping your code in a Router, so you should make sure that you’re doing that inside App or in ReactDOM.render:

import { BrowserRouter } from 'react-router-dom';

ReactDOM.render(
  <BrowserRouter>
    <App />
  </BrowserRouter>, 
  rootElement
  );

Next, your specific problem is that you’re rendering react-bootstrap’s Nav.Link instead of react-router’s Link component, so the router is not picking up your route changes. Fortunately, react-bootstrap provides a render prop in most of its components to specify which component or element you want to render if you don’t want the default. Switch to something like this:

import { Switch, Route, Link } from 'react-router-dom';

class Navigation extends Component {
  render() {
    return (
      <div>
        <div>
          <Navbar>
            <Navbar.Brand as={Link} to="https://stackoverflow.com/" >React-Bootstrap</Navbar.Brand>
            <Navbar.Collapse>
              <Nav className="mr-auto">
                <NavItem eventkey={1} href="https://stackoverflow.com/">
                  <Nav.Link as={Link} to="https://stackoverflow.com/" >Home</Nav.Link>
                </NavItem>
              </Nav>
              <Form inline>
                <FormControl type="text" placeholder="Search" className="mr-sm-2" />
                <Button variant="outline-success">Search</Button>
              </Form>
            </Navbar.Collapse>
          </Navbar>
        </div>
        <div>
          <Switch>
            <Route exact path="https://stackoverflow.com/" component={Home} />
            <Route render={function () {
              return <p>Not found</p>
            }} />
          </Switch>
        </div>
      </div>
    );
  }
}