Hi Achmidius, welcome to the forum:-)
Okay, so first of all ideally your EA should be robust enough to work well on most brokers and demo or live. An EA that only works on one set of broker data would not be good strategy to trade.
This is very straight forward to quickly test in EA studio thankfully.
Just open up a demo account with any other brokers you want to test your EA on. The upload their data to EA studio and then backtest your EA using the different broker data.
Your Ea strategy should perform in a similar fashion generally on the different brokers data. If it works well on one but poorly on another then that’s a red flag for me.