i know we would like to think the spreads matter on this, but its surely not the case. As Alec stated from Birts Comment ' When you start the EA' is what makes the difference.
Remember that the EA will fire a signal Only after a NEW fractal, in some cases, my brokers M15 candles will be different than yours, as a result, I get the fractal and the signal, and you would not.
If I got the fractal first and the signal, if you added your EA on the chart right after my signal ( lets say Buy on EuRUSD) and the next fractal is an UpFractal, you would then get a Sell Signal. Hence the huge variation.
I'll bet within 1 month, they offer a signal service to maintain the same trades across all the accounts. Just like FGB 😁