Source of data for cTrader chart without broker

Hello,

I'm trying a trading strategy based on my analysis on the cTrader chart linked to a Demo account linked to no specific broker (cTrader Desktop's "Open Demo Account" option under the cTrader button on top of the chart). I code using MQL4, and use BDSwiss's Demo Server for my test data, and the charts are very different. The strategy fails on MT4 but paper trading in cTrader is just fine. I'm now trying to figure where cTrader gets their data charts from, can anyone help ? Is it from a specific broker ? I can't find the information. I would then be able to trade from the related broker to have the same charts.

Thanks in advance.