Ok, my last attempt to explain the matter:

When you let a system terminate, you set Margin to 0, but continue already open trades. The purpose of continuing them is not giving up potential profit that would otherwise be made by the system. This means of course that pool trades still can open and close all the time, in order to match the virtual positions. If you just look into your log and compare the virtual and real positions, you'll probably see that exactly that happens.

If you do not want this, you must close the virtual trades. It is as simple as that. Preventing the opening of pool trades, but keeping virtual trades open, makes no sense.