It may be because of lactic acid bacteria fermentation, because of less salt and high temperature, so it is sour. You can eat it when it is sour, just like the sauerkraut process in the north. By the way, the secret of pickling radish is to master the pickling time and material selection, and the pickling method is also very important. Pickled radish should wait until after the first frost. At this time, the pickled radish has no bitterness and will not soak in the heart.
Remedial measures:
As long as the sour radish is not rotten, cut into pieces, copy with oil, and put a spoonful of sugar when copying, the taste will be good.