Kali AK Auto

That is 100% a magnesium deficiency! I know cuz i experienced the same exact thing in one of my first grows. Add some calmag with every feeding and the issue should go away pretty quickly. If you need any more help, feel free to message me! Good luck!

your plant is fine, the tips of dome plants burn like that when they are about to flower, you are running a auto and it is tie for that plant to start flower, remember now the plant is in flower and it is focusing energy to those bud sites, so now is the time to start using nutrients to feed those bud sites to get some nice fat buds, as far as the tips you could start dropping your dosage of nutrients, namely the use of nitrogen, as far as worry about those tips I would say if they are bothering you, take a pair of scissors and cut them off and you will be fine, either way though I would not be concerned, keep your eye on ph levels, and ph of your run off.