No positions opened: Maybe your portfolio had all zero positions? Otherwise I would not know a reason why positions are not opened.
Could you please clarify what you mean by zero positions? I didn't paper trade Z8 and Z9 before. No open positions in paper trading account. Asset List is default. I started paper trade Z8 (and Z9) from the scratch and received the message that Portfolio not changed. So, no shares are bought during initial run.