Angular 6 + RxJs 6 Refresh Token Interceptor - final retry cancels itself?

gistfile1.txt

@Injectable()
export class HandleUnauthorisedRequestInterceptor implements HttpInterceptor {
    constructor(
        private securityService: SecurityService
    ) { }

    public intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        console.log('intercepting ' + req.method + ' to ' + req.url);
        // Ignore all security controller requests as they're all dealt with separately
        if (req.url.indexOf('/security/') > -1) {
            return next.handle(req);
        }

        // Handle 401 responses from all other responses - attempt to refresh token
        // quietly. If refresh fails, log out and redirect
        return next.handle(req)
            .pipe(
                retryWhen(error$ => {
                    return error$
                        .pipe(
                            flatMap((error: HttpErrorResponse) => {
                                if (error.status === 401) {
                                    console.log('401 received - attempting refresh');

                                    return from(this.securityService
                                        .refreshAndHandle();
                                }
                                console.log('throwing...');
                                return Observable.throw({ error: 'No retries configured...' });
                            }),
                            take(1)
                        );
                })
            );
    }
}