Have you been able to check to make sure your buds are up to date on the software in the Wearables app? Have you been able to reset your buds through the Wearables app? You can do so by going to the Wearables app>About Buds>Reset Buds.
I would also recommend unpairing and repairing your buds from the Wearables app and Bluetooth menu after clearing the cache and data from the Wearables App. You can do this by navigating to Settings>Apps>Wearables App>(Force Stop the app)>Storage, from here you can clear the cache and data.
If you are still experiencing this symptom after performing this, I would recommend getting your device evaluated by a technician to diagnose and repair your symptom. I would be happy to look into service options for you. Could you please provide me with the model and serial number for your Galaxy buds in a private message to do so? https://bit.ly/2SUXRar
Let me know if this helps!