Because mklink /J "C:\Users\***\AppData\Roaming\Microsoft Flight Simulator\Packages\Community instead "C:\Users\giorgio\AppData\local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages\Community\Link Esterno" "D:\$FS2020 Community\Community Altri"
My MFS2020 is on Appdata\Local ...
Ciao
Giorgio Bolzano ITALY