New Quiet Comfort Earbuds no sound from left earbud

Didn't work me, I followed all the steps. They worked fine but suddenly one earbud (the left) stopped working and has no sound - only sound in the right. The right earbud blinks blue in the case after holding it whilst the left doesn't. Both blink white when put in the case. Any tips to solve this issue?

This issue goes back a reasonable time.