WSL paths are stored incorrectly

[Forside]

WSL file tabs are stored with incorrect paths into a tab group.

A correct WSL path looks like this (functionally a network drive path): \\wsl$\<distribution>\<path-to-file>.
When saving an open WSL file tab, the path is stored like this: \<distribution>\path-to-file>\.

This results in the following error when trying to open the tab group:

For reference: When hovering over the file tab, VS Code displays the correct path:

Tested on the version 2.1.1 from the marketplace. The extension was not installed or used previously.
OS: Windows 10 21H2