Anyone know why my dieffenbachia leaves are turning yellow on the bottom? I've had it for about 3 months. I switched the soil about a week or 2 ago. It seemed like it adjusted well but over the last few days, leaves have yellowing super quickly. I just cut off 3 yellow leaves yesterday and now leaves that were green yesterday are yellow all of a sudden again. Any idea what this could be? Should I switch back to the original soil or could there be another problem? Pic on the left is when it was thriving. Pic on the right is what it looks like today.