Problem with wio terminal and Grove Multichannel Gas Sensor v2

I am experiencing difficulties while conducting scent detection using the Wio Terminal and the Grove Multichannel Gas Sensor v2. During the training mode, the detection results do not match the expected outcome. It should detect “ambient (surroundings)” initially as there is no smell present, but it instead shows “coffee”.

Furthermore, when I attempt to detect the scent of hand sanitizer containing alcohol, the result indicates “Whiskey”, but the machine freezes when displaying the percentage (%) likelihood.

I would like to ensure more accurate scent detection results. Are there any suggestions or steps I can take to address these issues? Thank you.