Running into error with ChaCha

I am using the basic ChaCha setup found in the User Guide `autovw = AutoVW(max_live_model_num=5, search_space={'interactions': AutoVW.AUTOMATIC})`

however when running the line: `autovw.learn(sample)` where `sample` is a VowpalWabbit formatted string that works well on a regular (and separate) VowpalWabbit environment, I get the following error:

```
[/usr/local/lib/python3.10/dist-packages/flaml/onlineml/autovw.py](https://localhost:8080/#) in learn(self, data_sample)
173 """
174 self._iter += 1
--> 175 self._trial_runner.step(data_sample, (self._y_predict, self._best_trial))
176
177 def _select_best_trial(self):

AttributeError: 'NoneType' object has no attribute 'step'
```
Note I am running this on Google Colab. Anyone ever encounter this before?