deep learning model based chatbot problem

[ironside007]

I have made a ChatBot working with Udemy's "Deep learning and NLP A-Z™: how to create a chatbot course".
I used NLP for data pre-processing and deep learning for training the model. Now that the model is trained,(ISSUE: ) whenever i ask a question to my chatbot it repeats the same answer for every question and each time i run it again there's a different constant answer.

Hyperparameters chosen are:
epochs = 40
batch_size = 128
rnn_size = 512
num_layers = 3
encoding_embedding_size = 512
decoding_embedding_size = 512
learning_rate = 0.01
learning_rate_decay = 0.9
min_learning_rate = 0.0001
keep_probability = 0.5

Training dataset: Corenll movie dataset

PS: I followed every step same as in the tutorial.