Bug - simple shortcut script to calculate folder size doesn't work

I have written this simple shortcut to calculate a folder size:

https://www.icloud.com/shortcuts/bc135fad3a3948bc854ec88f76c4df60

Unfortunately it does't work.
It seems a bug with the "execute shell command" action when pickFolder is used. After pickFolder is used a-Shell returns immediately and does not execute the subsequent commands. Then the "Get File" action does't find the file.
But even if I try to execute the command twice, after getting back to shortcuts app, the folder is NOT the one chosen by the user. Even if the shell prompt shows the selected folder, the commands executed are executed in the ORIGINAL folder (Shortcuts).
Please fix this. Otherwise there is no way to calculate a folder size with a-Shell. And that is a pity, because the standard get folder content action of siri shortcuts is slow as hell.

P.S.
It would also be great if a-Shell pickFolder would accept a folder path as argument, so we would be able to pass that with the share menu inside the Files app.