Captcha solver CNN overfitting problem

So I was trying to make this model to solve a captcha, dataset containing 82k imgs of 5 char captchas, one hot encoded captcha text as the labels, the model is overfitting with high variance no matter the regularization / drop out,

model:

D = 5 #no of chars in the captcha ## 128 total possible char space (ASCII)
model = Sequential(\[
Conv2D(32, 3, activation='relu', input\_shape=(H,W,1), kernel\_regularizers=regularizers.l2(0.001)),
MaxPooling2D((2,2)),
Conv2D(64, 3, activation='relu', kernel\_regularizers=regularizers.l2(0.001)),
MaxPooling2D((2,2)),
Conv2D(64, 3, activation='relu', kernel\_regularizers=regularizers.l2(0.001)),
MaxPooling2D((2,2)),
Flatten(),
Dense(1024, …

captcha char cnn dataset deeplearning hot labels overfitting regularization solver text variance