Yellow Cotyledon and brown tips.

Je pense que tes pots sont vraiment trop petit et du coup trop arrosé, Je commencerais avec la taille d'un yaourt minimum pour que les racine puissent se développer un minimum.

hey there, so the overwatering is releasing too many nutrients from the soil which is leading to burning. you need to follow a strict wet dry cycle. i know the seedlings dont like it dry but you do need it to dry out otherwise this sort of thing can happen. Just keep doing what you're doing just let the medium dry out. Hope this helps ! 🚀

Hey buddy ;-) that could come from the wet :-) there is a very simple trick when you give water. Let it dry nicely, then lift the pot up and remember how easy it is. Then pour it and lift the pot back up and notice how heavy it is now. The next time you water, you will only do it again if the pot is as light as when you started. As a pure beginner, you can also use a scale and note the weight ፦). Keep carrying as before 👍 Your plant is beautiful