When creating a dashboard line graph, in this example drive c: and d: disk usage, the Graph or Chart can show at the start and at the end of the graph an invalid downline to 0. This gives an invalid impression to end users that something is wrong:
Release : UIM20.4 cu3 on windows 2016
Component : UIM OPERATOR CONSOLE - DASHBOARDS/DESIGNER
The code defect caused this behavior.
Upgrade your UIM environment to 20.4 CU4.
https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/release-announcements/CA-Unified-Infrastructure-Management-Hotfix-Index/7233