Ergänzende Veranlagung zur Quellensteuer - Zurich

Hello, I have received today a letter from Zurich's Kantonales Steuermat titled:

Stuerrechnung

Direkte Bundessteuer 2019

Ergänzende Veranlagung zur Quellensteuer

If I understood correctly, this is the final bill. I'm on Quellensteuer but had some additional income from bank investments abroad that I declared.

The letter contains Berechnungsgrundlagen with some calculations relevant to income I declared. And in Abrechnung it says: Ihr Guthaben: -1'800 . And invitation to send them my bank account number for the transfer.

Now, I am very happy to receive this money only I am wondering why they are giving me the money back as this is the same amount I paid as requested in Provisorische Rechnung in 2019, based on " Schulden " which I believe were due to this additional income I had.

Any idea someone?

I also paid Provisorische Rechnung for Staats und Gemeindesteuern but that was just 180 chf. Could they then ask me to pay 1800 chf to them? Not sure how it works and which entity collects tax for which type of income.

Thanks