Hey, this is a known bug in 2.6.20. It affects the sidebar titles like Explorer, Run and Debug, and others when the activity bar is set to vertical.
For now, you can work around it like this: Settings → search for workbench.activityBar.orientation → set it to horizontal. The Explorer title will come back.
Yeah, but the command center now quickly appears and then converts into the root folder name. Useless! And if i set the option “debug.toolBarLocation”: “commandCenter”, now i don’t see it anymore because a useless folder name appears in its place.