In my experience, I run into this condition every now an then. Usually it's from some damage to the pod and the plant is aborting the pepper. Sometimes the damage is small like from a stink bug. Could be mold on the inside too that caused the plant to discharge the pepper. How many peppers show this?

like 4 or 5 peppers

I would inspect for damage, most likely the cause, since it's an otherwise healthy plant.