This default timeout for SDDC manager UI needs to be adjusted. This article describes how to increase or decrease the session timeout for SDDC Manager UI.
Resolution
The following steps allow the UI timeout to be set in SDDC Manager:
Login to SDDC Manager
Click on the drop-down on the top right
Click on Preferences
You can set the session UI timeout to be 1 hour, 2 hours, or 3 hours.