Speed Passion 2.0 problem

[Ell678]

Hi all! I bought myself a Speed Passion GT2.0 ESC a while ago along with a brushless Speed Passion 8.5T motor along with the programming unit / software. However I'v noticed after racing for a while there's a slight problem. The boost / turbo functions are enabled and they do work but after a while in a race they just cease to function, then re-enable a while later. I thought for a while this may be down to the overheat protection but after racing with both a B4 and a Cougar (former with cooling fan, latter without) it doesn't seem to make a difference. I don't really want to turn off the protection in case it does overheat and I'm down an ESC with no immediate way of buying another. Has anybody else had an issue like this with the ESC?