Strange graphical artefact in Studio

Hi all, sometimes in Studio I can see a strange graphical artefact. Anyone knows what this is? I have attached screenshot (it is the white square-thingy in the lower left hand side).

Studio 2019.10.4 - 2/6/2020
Enterprise License
Windows Installer

License Provider: Orchestrator
Activation ID:

Microsoft Windows Server 2012 R2 Datacenter 64-bit
.NET Framework Version 4.7.2 or later

This looks you have selected overview option in the work space area.


Thanks for the reply. Do you know how I can fix this?