please find below steps to reproduce the token issue 

Steps to re-produce the issue:

1. Create new API credentials in Jenkins and pass that token as Environment Variable in Jenkins Script.
2. In Jenkins upstream pipeline, add stage to download artifact from downstream pipeline by accessing Jenkins URL using the API credentials which is mentioned in Environment Variable.
3. The pipeline will fail due to 401 Access Issue while trying to access URL to download artifact.
4. The same pipeline will work for minimum 2 hours once we open the Jenkins URL in Jenkins Windows machine manually and tried to run the pipeline from Jenkins Website locally without any issue.
5. After 2 hours, if we try to re-trigger the pipeline again its failing due to 401 access issue while trying to access URL to download artifact.