Get yourself checked out to rule out any underlying issues.
Some questions I would ask:
It might be that your body is still adjusting…it’s good that way. And you might have to adjust to its adjustments.
Is the diarrhea happening during your fasting window or after you eat? If it’s after you eat, it’s normal. Your body is producing less enzymes for digesting food in the fasting window. So when you eat, there aren’t enough enzymes and so your body is not able to break down the food as it normally does so the body is going to release water to flush it out which = diarrhea. I suggest taking 1-2 tablespoons of whole psyllium husks about 15 min prior to actually eating anything. It slows down the digestion.