Hey Gaz
Yes, I guess the access token has an expiry of 5 minutes. You can check it by inspecting the access token, eg putting it in jwt.io. Do you use any library for authentication, if yes which and how? If you build it yourself, you likely need to use the refresh token to obtain a new access token (see eg the TokenRefresher.ts class in solid-client-authn-js. This is related to the answer from @zwifi in the other thread.