Unable to retrieve source after successful authorization in VSCode

I created a project with manifest. When I right click on package.xml and click ‘Retrieve source’, VSCode is repeatedly giving the following error even after successful authorization of the org:
ERROR running force:source:retrieve: core_1.fs.fileExists is not a function.

This is happening only on few projects. When I try to authorize other orgs from the same project, even then it gives the same error.

Any ideas? I have run sfdx update multiple times on the terminal and still no luck.
Alternatively, may I know how to reach the vscode support team?