Any ideas on this issue

So started a grow 3 weeks ago everything going great 2 auto banana blaze usually just nl autos cos most others I tried tasted crap or didnt yield much .
They were fine the whole time then I check em this morning and one leaf looks either eaten from the rope side or it's some sort of deficiency.
Any input would be appreciated hoping they will be done for christmas in case local supplies are dry over lockdown

More info would help , but check ya ph is in range for the medium ya using ,