• Hold down the Windows key and press R to bring up the Run dialog.
• Type gpedit.msc and press Enter. You will need administrator privileges to continue.
• Navigate to User Configuration > Administrative Templates > Windows Components > Attachment Manager.
• In the right-side pane, double-click "Do not preserve zone information in file attachments", set it to Enabled, then press OK.

wsl.exe --shutdown
cd ~\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\
optimize-vhd -Path .\ext4.vhdx -Mode full