Ea backtest mt5, different brokers different results

Hello I have been backtesting an ea. Same time period( all year 2018) on two different brokers and I have two completely different results. The modeling quality is 100% on both brokers yet one shows an amount of trades of 465 while the other only shows 240. The one with less trades is incredibly the most profitable (3x more profitable than the other) and it has the higher spread between the two. Why do the results vary so wildly between the brokers? Test was perform on a h1 timeframe. Also I tried a number of other ea to see if I got the same differences and some do differentiate massively between brokers while others differentiate way less. Is it a problem with ea or broker tick history( despiste on the results claiming 100%)?
Thank you for your time