Hibiscus disease

My Hibiscus plant has been witnessing this disease for the past several months, which clings to the stem of the plant and stems into the white stem and spoils the plant, which can tell which disease it is What is its medicine

If any of you know about the disease of this plant, then please tell me because I have done a lot of medicine and there is no improvement in my plant. I was told by the previous group that you can change your soil and see this problem. Once I get rid of the soil, I will change it, I will update youyou