HTTP request falling into catchError

I'm trying to do http request inside the httpInterceptor, however it always falls in the catcherror, it is printed on the console the "fell into err".

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const authToken = localStorage.getItem('token');
    let headers: HttpHeaders = new HttpHeaders();
    headers = headers.append('token', authToken);
    headers = headers.append('Authorization', 'bearer '+authToken);

    if(authToken != null){
        if(req.url !== AppSettings.API_ENDPOINT + 'plano/busca'){
        let http: HttpClient = this.injector.get(HttpClient);

        return http.get('api....', {headers: headers}).pipe(switchMap((response) => {
            console.log('caiu no res')
            console.log(response);
            const newRequest = req.clone({
                setHeaders: { Authorization: 'bearer ${authToken}', token: '${authToken}' }
            });
            return next.handle(newRequest);
        }),
        (err) => {
            console.log('caiu no err');
            if(err instanceof HttpErrorResponse) {
            console.log(err)
            return Observable.throw(err); 
        }}
    )}else {
        return next.handle(req);
        }
    }
}

@Edit:

I tried to make the request inside the service, now I get the request return, but it is not cloning the request and adding the header:

intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const authToken = localStorage.getItem('token');
    let headers: HttpHeaders = new HttpHeaders();
    headers = headers.append('token', authToken);
    headers = headers.append('Authorization', 'bearer '+authToken);

    if(authToken != null){
        if(req.url !== AppSettings.API_ENDPOINT + 'plano/busca'){
        let http: HttpClient = this.injector.get(HttpClient);

        this.authService.validaPlano().subscribe((res) =>{
            console.log(res);
            if(res.data.vencido == true){
                this.authService.Logout();
            }else{
            const newRequest = req.clone({
                setHeaders: { Authorization: 'bearer ${authToken}', token: '${authToken}' }
            });
            return next.handle(newRequest);
            }
        },
        (err) => {
            if(err instanceof HttpErrorResponse) {
            return Observable.throw(err); 
        }
    })
    }else {
        return next.handle(req);
        }
    }
}
}

I have already checked and the headers are working correctly, I tested the postman and the request returns a response json ... Why might be falling into err?