Hello I am having some problems with growing an epiphyllum ..it has been multiple times i start rootings and almost everytime they die after months of growing well... i had one doing well now but just noticed yellowing and softening at the stem of it’s major leaf. I know this is probably something wrong with my watering but woukd like to know if there is anything i can do at this stage to save the plant or if it is already too late... thanks for your help!!