EA works attached to single chart, messes up with multiple charts

Hi all, I wrote a EA which facilitate live trading operations, and it works correctly when attached to a single symbol chart, but messes up things when attached to multiple charts. What I mean is: when attached to multiple charts, EA ( upon input from the trader ) opens a trade operation on a symbol chart, then some operation are executed by same EA attached to DIFFERENT symbol charts, such as execution of a custom Inform() function which prints some text on the chart window, text which contains the number of the order opened in the first chart.

Now I really cannot understand why and how is even possible that an EA attached to a chart will pass a parameter ( like the order ticket ) to an EA attached to a DIFFERENT chart, since this EA does not use GlobalVariables of the Client Terminal.
How is that possible? How can an EA trigger the execution of functions and pass parameters to an EA attached to a different chart?

Are you using magic numbers?

EA selects orders by their numbers ( i.e. tickets ).

It will open an order based on trader's action ( there's a line on the chart, moving that line commands the EA to open an order ), and it will get the order ticket.

After that, order will be selected by ticket number when needed ( EA will place stops, move stop to break even, trail the stop, etc. )