There’s so many potential factors, its hard to say what is causing it. You could have a histamine problem, you could have liver issues, you might not be detoxing enough, you could have an immune disorder, etc.
If you don’t kill it off aggresively with large doses of antifungals, it could also be getting killed and then coming back (if fed by things such as rice, fruit, pork, etc) and thus the numbers don’t change.
You might also have a different gut flora overgrowth due to low levels of HCL (hydro-chloric acid), etc. Something else might be thriving in there, we just don’t know.
Some people who don’t detox enough have the candida toxins recirculate throughout their bodies and it never gets released.
How high of a dose of antifungals have you worked up to?