Hi. I write for help dealing with the asset SPXL, whose old symbol was BGU. 

Attached you have a backtest which shows my issue. I am asking for SPXL quotes, before the symbol change. QuantConnect properly returns the quotes with the old ticker name (BGU), which at that time is correct. The problem is that with this way, I have to deal with the symbol name change. 

Is there any way I can work with only one symbol name? Please, take a look to backtest logs, which helps to describe the problem.