based on your latest share of grader output which provides information which codes were incorrect,
for UNQ-C1 grade function code correction refer the below link, your code for one hot label, needs to use the keras categorical function and Use np.moveaxis function to check the dimension, numerical are mentioned correctly in the brackets(below link comments should help you understand how both codes need to be corrected
For UNQ-C3 codes correction, your code implement needs to be the way you implemented in UNQ-C4. Do not include 2 in denominator for the last equation while calculating single soft dice coefficient. 2 need to need to be mentioned for the dice_numerator. compare the code implement with UNQ_C4 codes you wrote. Also in UNQ_C3 you used tf.reduce (incorrect function) where as in c4 you used K.sum. You are suppose to use the same function you used in UNQ_C4 i.e. K.sum.