| It looks to me as if it may have both a issue with either sunburn or chemical burn with a secondary bacterial infection ( the black spots) If the plant had wet leave and the sun hit them for awhile or you tried a new spray that could cause it. The Bacterial infection I would believe is a secondary infection caused by the first problem. If this was my plant I would remove the worst of the leaves and spray the plant with Physan 20 and keep it away from the rest of the plants for a few weeks to be safe.
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