I have had this ficus tree since January 2021. It has slowly been losing leaves. It doesn't have any pests but did have red spider mites was able to successfully get rid of in 2021 after using horticultural oil. I use beneficial mites now. I repotted it in 2023 and have tried different fertilizers over the years to try to fix the problem. It looks almost like a nutrient deficiency but I have tried iron, calcium, magnesium ect. With no change at all. I am wondering if maybe this is a disease. All leaves that eventually fall end up with some whitish dried sap at the base of the leave before the leaves start yellowing. I do not want to lose this tree and am hoping someone can help me. I am making sure not to over water too so don't think it has root rot. It is in a north facing window but has several grow lights. In the pot it is around 9 feet tall. Has anyone seen anything like this before and how did you treat it?

Hi & welcome! Are you able to add a pic of your whole plant, with the pot? Do Ficus have extrafloral nectaries? I don't know. Does the pot have a drain hole?