Certified GKH Gardening Expert
This appears to be a bacterial or fungal infection.
There will, likely, be some issues with the leaves as well. A fungicide will be necessary to clear up the disease. The fruit will still be edible, but will be unsightly.
Make sure the soil gets a chance to dry out very thoroughly, down to about 4 inches between watering. These plants are quite drought tolerant, but will not tolerate wet soils. Underwatering will be much preferred to overwatering.
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