Definitely nutrient burn, do not give any fertilizers for at least 2 weeks then start with one quarter strength before going to half strength 3 weeks later.
Autos can get by happily on no more than half strength nutrients their whole lives when growing in soil.
Also, 24/0 is bad for any plant, including cannabis.
Cannabis NEEDS sleep and 18/6 is optimum for a healthy metabolism.
Cannabis, all plants really, need sleep to finish their photosynthesis cycle and have a correctly functioning life.
The myth that growing cannabis for weeks/months without sleep needs to be erased from the internet, only someone who does not understand photosynthesis and how plants function would spread the rumor that growing at 24/0 is just fine. It definitelt is not!
Anyway, enough of my rant, it is not too late for your baby, you will not lose anything by going to 18/6, in fact you will gain much due to the plant having a correctly functioning metabolism and proper health, just don't feed it for a while, the soil is hot.
Hope this helps, Organoman.