Problem with changing stock over multiple periods

Hi,

I recently started using the programme and it is very helpful.
But I found a problem and I don't know if I did something wrong or there is some bug.
I created a composting plant in STAN and there is one process with a stock. I wanted to model the plant over one year and I gave the stock a starting value of 3.609 t.
The programm calculated a stock change of +1.203 t for the first period. But when I open the second period the value isn't 4.812 t as one might expect but 3.709,25.

Has that happened to anyone else?
Even with a starting value of 0 I dont get the proper results.

Thanks ahead of time!

The problem is that you entered your flows with the unit t/a while looking at periods of length 1 month. This leads to the correct solution:

3,609 t + 1,203 t/a * 1/12 month/a = 3,709.25 t

To fix your problem, change the units of your entered data to t/mon instead of t/yr.