Ambari View impersonation, converting to uppercase

[#1]

Hello,

I am using Ambari 2.4.2.0 on HDP 2.5.3.0 and after logging in to Ambari with lowercase username, my user gets converted to UPPERCASE while being impersonated by the Hive View e.g.

Why does the Ambari-View convert the current user to uppercase username for impersonation. Is this a feature or an issue ?!?

logged in as lowercase user:

corresponding audit entry in Ranger with uppercase username:

Thanks in advance...

[#2]

@Gerd Koenig

I don't think Ambari views convert usernames into Upper case. do you have any authtolocal defined at core-site? converting usernames to Uppercase?