Invalid Response

Hi, I am using the Okta for handling the login system for a while.
However, since the beginning of this week, the problems came up, and I need your help.

After I login via Okta, I will send a request for fetching data, but the response I got is
Preformatted text"Error while resolving signing key for kid “p_FquW9CwaXgmPEAx7SEcNwKMq-ZaywndE5uUyiRsCE” "
and the status code is " 401 Unauthorized "

Here is what I am setting for the default config file:
one is for the server:
module.exports = {
resourceServer: {
port: 5000,
oidc: {
issuer: ’
assertClaims: {
aud: ‘api://default’,
cid: ‘xxxxxxxxxxxxxxxxx’
another is for the client side:
export default {
oidc: {
clientId: ‘xxxxxxxxxx’,
issuer: ‘’,
redirectUri: ‘http://localhost:3000/implicit/callback’,
scope: ‘openid profile email’,

So is there any problem for those default config file or any solution for this problem?
Thanks a lot for any help!