Does upload zone II work?

Does upload zone II work? I uploaded a mixed track in zone I plus an isolated bass track in zone II, but it did not work as expected. The track had no visual wave form and when I clicked on download there was no bass track.
So I used the old method and by after uploading and publishing the track I go to edit and upload the isolated track. This works fine.
Still wondering how to use the zone II.

Have a good day!

Bas

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