thats not led burn. that plant looks like its drowning more than anything else or ph maybe.
you should fill out the troubleshooting form. need to know a little more.
it isnt the light tho. I have some seriously extreme led lights and i can get both of them within 12-18" with out any problems
and i have uv leds in my spectrum as well. if anything was really gonna burn it itd be uv.
10" inches should be fine. more room is always nice if you have the space and light to fill it.
try running both red and blue and see if it helps. plants still use some red in veg and blue in flower.
but we need to know about the soil ferts ph, watering sched. autos so light cycle dont really matter as much.