LED Tail Light Issue

[Daskoff]

I bought my truck with LED lights already on so am not sure what brand it is but the issue I have is when I turn on the left indicator I get a fast blink. All lights work and the right indicator blinks normally. In a non-LED situation when there is a fast blink it means a bulb is out or the rely is bad but in this case everything works fine - lights, blinking, reverse and brake lights all work. I am not familiar with the LED system so not sure if I have to change the tail light units or if there is something else I have to chase.

Thanks,