As much of a question as there is info π
So I wouldn't mind some pepper.
That's classic salt buildup in coco β yellowing, tip burn, and leaf curl all over. You need to flush the substrate with 2β3x pot volume of clean, pH 5.8β6.0 water to wash out excess salts. Then resume light feeding after they recover. Coco needs frequent runoff to stay healthy β always aim for 10β20% runoff every watering.