Try the following troubleshooting: 

1. Try other sizes of eartips to ensure the one you're using fit well and create a tight seal.
2. Make sure you're wearing the earbuds correctly so that they create a tight seal. To check if you're wearing the earbuds in the perfect position, take the Tip Fit Test on the Soundcore app and watch this video for more information.
3. Try different noise cancellation modes to find one that's most suited to your environment. You can also customize the EQ to tailor the sound to your ears.

Note: In a noisy environment and at high volume, you may feel that the noise cancellation performance is not as strong.