paypal webhook failures

Hi we are having a very strange issue.

After weeks of troubleshooting mostly we have our GiveWP setup working and payments succeeding without much problems. There is however a persistent webhook failure reported in GiveWP logs.

It seems even after completing payments, payments coming off account, marked as completed at GiveWP side there’s one last webhook which keeps failure.

We managed to narrow it down to an access token issue, it seems PayPal is expecting an access token for this last attempt which it is not receiving.

This problem happens regardless whether any caching is running or not, we’ve testing this with every single kind of cache completely disabled and clearer and it still persists.

We’ve removed everything that we thought could have been interrupting the process of communication between givewp and paypal including security patches and plugins.

Part of the webhook failure log contains the following

[body] => {"error":"invalid_token","error_description":"Access Token not found in cache"}
    [response] => Array