tokenizer(batch_sentences, padding=True) - padding to max sequence in batch
Maybe you wanted to use:
tokenizer(batch_sentences, padding='max_length') - padding to max model input length
This was taken from the docs:

  
      
      huggingface.co
  
  
    

Preprocessing data 8

In this tutorial, we’ll explore how to preprocess your data using 🤗 Transformers. The main tool for this is what we call a tokenizer. You can build one using...