Ci4 OAuth2 ACCESS_TOKEN invalid

[Revitando]

Hey,

im creating a website with an Ci4 RESTFul backend which is using your oauth2-server-php package.
A few days ago everything seemed to work quite fine but currently i have the following problem:

When I recieve my bearer token at lets say 8:00AM:
{ "access_token": "b3aaee2354629f4b4035d63acdc0ce7be29a0210", "expires_in": 3600, "token_type": "Bearer", "scope": "app", "refresh_token": "3bac20f4ee327633f169e322343c99a008727fca" }
I would assume that the token would be valid at least until 9:00 AM.
But if i take a look at the database, the token is valid until 8:00 AM.

Even if i change the "expires" to 9:00AM I recieve:
{ "error": "invalid_token", "error_description": "The access token provided is invalid" }

I tried to change the expires_in in "vendor/bshaffer/src/ResponseType/AccessToken" to "43200" (12h) but the token still expires_in 3600.

Coukd you tell me what im missing here?