The following issue when using multiple brokers has been raised before:
#include <profile.c>

function run()
{
BarZone = WET;
BarPeriod = 1;
LookBack = 0;

asset("USDCHF_Broker1");
printf("n BALANCE %f",Balance);
asset("USDCHF_Broker1");
printf("n BALANCE %f",Balance);
}

The Balance that is printed is in both cases the one of the broker account selected in the zorro window. When inserting a trade command, trades are opened with broker1 and broker2, so I am sure that the Accounts.csv as well as the asset file are correct.

I received the feedback that this issue has been solved, but I can not confirm this. My results contradict this.