Week 7 of flower autoflower Dont know what this i...

... i'm about to throw out my leaf chart and just memorize that video, lol

As bred said,there could be a number of reasons for it.Is it only on the older fan leaves as that will give you some idea.Its normal for the plant to put everything into to flower at this stage and the older fan leaves are the first ones to suffer so I wouldnt worry too much

Don't want to seem rude or anything but we need more information to be able to tell what can be wrong with her. If we are talking about the Guava Auto in your diary I saw you have a feeding plan. And she gets her nutrients but the next things to see are 1. How often do you feed? 2. PH of the water + nutrients solution going in but also it can help to look at the runoff PH as well 3. EC or ppm? if you get familiar with either EC or ppm and measuring them it will tell you roughly how much nutes she gets and eats 4. Soil temp and temps at night. I too had 24 C in the tent i thought it's good and then in the soil 19C for the plant nearest air intake. Just eyeballing it I would say it's a combination Prob Soil PH out of whack to alkaline. and from there it's a heap of problems. I'd say start with that and then see how it progresses. I think she prob needs phosporus, kalium and prob a little nitrogen too. But start with the soil, take a look at the things i just listed and then inform us. We could prob help more. 😊 Don't stress too much either, we are all here to learn. Wish you a good one and that your girl heals quick.💪😊

Looks kind of like a ph swing or calcium issue. The plants drink a lot of water during flower. If you let it get too dry in the substrate, calcium and ph can be affected causing a swing. Check your runoff for ph and ec and see where you are. I also see you use a wide variety of nutes. To each their own as far as feeding goes. I wonder if the ratios are still good with everything you're putting in though. Best of luck! Happy Growing!