Weather prediction and Windy.com fail! Eleuthera to Exumas

Predicted: 11 kt wind + 0-1ft swells Actual (my observation): 20 kt (35-40 kt gusts) + 5 - 6 ft breaking waves 25-30 boats all did this crossing within an hour of us. We all thought it would be a calm sail and we thought wrong. 12 hours later, still nasty over 100 sq miles of ocean and Windy still thinks it's benign. Odd? Normal for Bahamas cruising?