C-1/20 – Finanzamt Wien
raised by AT
C-4/20 – ALTI
raised by BG
C-7/20 – VS
C-9/20 – Grundstücksgemeinschaft Kollaustraße 136
both raised by DE
Unfortunately, at the moment there is no further information about the background of these cases.
If you have any further details (e.g. about national case law leading up to these questions), please let us know.