RuntimeError: Expected all tensors to be on the same device

I’m getting this error message when I try to use my fine tuned ELECTRA model to classify a batch of sentences, but not when I’m using it to just classify a single sentence.
Here’s the chunk in which I get the error:

# FRACTION of dataset
test = congress_113_tweets.head(10)
test.head(1)
# LIST of text variable dataset
list_text = test['text'].tolist()

def run_model(list_text):
    # tokenizing comment ^
    encoding = tokenizer.encode_plus(
      test_comment,
      add_special_tokens=True,
      max_length=512,
      return_token_type_ids=False,
      padding="max_length",
      return_attention_mask=True,
      return_tensors='pt',
    )

    # returning probability values for each label
    _, test_prediction = trained_model(encoding["input_ids"], encoding["attention_mask"])
    return test_prediction.flatten().numpy()

#Then, apply the function to each row:
test[LABEL_COLUMNS] = test[['text']].apply(run_model, axis=1, result_type='expand')

My dataset looks like this:

ID              text
1                People are now using @metronorth like a subway...
2                Spent morning on @metronorth issues with Rep. ...
3                Step dancing, boiled meat, and beer at the Hib...
4                What a reception for #Team26 in Greenwich! htt...

Here’s a link to a colab containing all the code: Google Colab