Remote_Senser:

My dataset only contains values between 0 and 1


first, you should check your model output, not your dataset.
Second, l1 norm also computes sum of all difference in one dim. Although your data is 0-1 range, l1norm could be greater than one i.e. L1([.5,.5,.5]) = 1.5
also as @Apurv25  said, you can change beta .