It's probably the adjustable resistance adjusting the amount of brake you push. No matter if its a expensive resistor or a cheap one this can be destroyed over time.
It could be a simple thing like dust making the resistor don't get back to "limitless" position or the resistor just cant make the resistance limitless.
How long did this pedal work before this happen? I mean products today are made to last about the warranty time and that's it. And you didn't really only used this for fun a couple of time a week. You pushed those pedals to the limit like everyone here does
I'm not going to defend pore made products, but it's how the world work today with it's buy and throw mentality, so products can be re sold..
Atleast cheap plastic products like the DFGT pedals are.. You should look to
fanatec The more money you put in it the longer they MIGHT last.