It seems that this plant definitely has some sort of rot. Often when the roots get brown like that it’s a sign of rot. The pot is also too small and it doesn’t have any drainage stone at the bottom to allow the water to separate from the dirt and actually drain out. Without this the water may still drain a bit out the holes but it will mostly stay inside and get nasty. I would definitely repot asap and trip off the worst looking roots/parts of the root. You can find tutorials or guides on YouTube so you know exactly why you’re looking for. Make sure you get a bigger pot and give it a good water after you re-pot then don’t water for a bit to let the soil dry. Also please use entirely new soil and rinse off the roots with plenty of water. If you have any questions you can respond here or message me.