jus a bit of overwatering combined with the point of the lifecycle it's at. At this stage most of the action is happening in the soil not outside . nothing to worry about, just transplant when you're ready... or do the solocup challenge :-) hope this helps ! 🚀
Hello it is an overwatering be sure you have holes at the bottom of your cup to drain the water. Wait until your soil dry and it will recover soon. Good job.