Best answer by Max
Since this topic is growing and its becoming harder to search through it I have made a full guide of troubleshooting steps to hopefully facilitate you more.
The first step to try when one of the buds are seemingly lower toned or not working would be a Factory Reset to the Freebuds - How to Restore Factory Settings on FreeBuds :
• Open the charging case, put both FreeBuds inside, and leave the charging case open.
• Press and hold the function button for 10s (seconds) or more. After the indicator blinks in red, green, and blue, your FreeBuds are restored to their factory settings.
Depending on the device you are using with the Freebuds some users have noticed that a cache clear and data wipe of the android bluetooth app would resolve the issue they where experiencing.
After any such actions a unpair and repair of them with your handset is advised and of course make sure that you are using the latest software .
In situation that the issues still persist even after the troubleshooting steps and you have tested them with another device, the freebuds would have to be sent to our service department for a more hands-on approach.
To facilitate such a need the Huawei company has several different options depending on the region you are residing within https://consumer.huawei.com/en/worldwide/ .
For the UK region that we cater to on this medium you may contact our techsupport channels via mail, chat or hotline (free of charge of course 08000886700 Monday to Friday 9 am to 9pm Saturdays 9am to 5pm) at https://consumer.huawei.com/uk/
To ensure a speedy process please bare in mind that the operator would need your private details such as Name; Model type; S/N; any documents related to the device, etc - please do mention that you have done the troubleshooting steps as mentioned on the forum and they will proceed to facilitate the service process.
And as always if you need any further assistance please feel free to contact us via forum or via mail, chat or hotline at https://consumer.huawei.com/