Datasource Headers are now hidden
This behavior has been introduced in Elements Connect 8.0.2.
Symptoms
After upgrading to version 8.0.2, header values defined in datasources are now hidden:

Cause
Tokens in headers are now hidden in datasource configurations, so any sensitive and confidential information remains private.
Resolution
No action is required. A header value that appears to be hidden is still saved correctly and remains unchanged.
If you need to confirm that a header value is valid, delete it and re-enter it.