Not sure what you mean about stagnant roots. Your plant looks healthy.

You need to tell us where you live, how you are growing it, light, indoors, outdoors, watering.

Jane

Thanks jane, if you look closely, those black spots that are on the stem are roots that started to come out and never developed. I live in Florida and my plants are in a room with enough light. I want to transplant this plant and cover this part of it with the substrate but I fear that this causes me a rot in the stem so I am asking for advice, greetings.

I cannot see the black roots. Maybe post another pic which can be enlarged.

Is your plant still in bloom? Is this plant going outside?

You can repot now, since you are in a warm climate. I would pot it in a mix of small/med bark mixed with some sphag.

Jane