I noticed my C. taitungensis x C. revoluta has begun to rot at the apex. It had suffered some freeze damage to the fronds over the winter. When I was cutting these away, I noticed the top of the caudex was soft and mushy. I poured some fungicide on it and now am unsure what to do next. Can it be salvaged? It is over six years old and has never had this type of damage before. Any help would be appreciated. Thanks.