I have a question to experienced traders.

Now I am trading with MT4.
My strategy is short term (3s - 1min). I put the same EA on 3 terminals.

Terminal 1: located at VPN in NY, connected to Server A of IC Market, lot size: 5.0
Terminal 2: located at the same VPN, connected to Server A of IC Market, lot size: 0.5
Terminal 3: located at the same VPN, connected to Server B of IC Market, lot size: 0.2

I assumed the trade results will be almost the same.
However, the results were totally different.
First, there were much more trades in Terminal 3, and almost no trade in Terminal 1 and 2. There was no message in Terminal 1 and 2. This means, the trades were even not triggered.
The profitability per trade was also different.
I have checked the utilization of my VPN server, but the utilization of CPU and Memory are around 30%


Do you have ideas what are the reasons?
I think it caused by some mechanism of MT4 server's filling orders, but I do not know the mechanism.