Buds 3 Pro left side All treble

Hi @XJCAR, thank you for reaching out to the Samsung Community. Having the bass go out on your left bud when your right one goes in the case is not typical behavior and can definitely get frustrating. I would love to help you out with this. 

First thing to try is making sure your Buds are on the latest software version. 

Next, check your sound accessibility settings. Navigate to the earbud settings >tap accessibility> and then move the balance slider to the left or right until the volume is equal.

If that didn't resolve the issue restart and reset your buds. To manually restart the buds insert the earbuds into the charging case and close the lid. Wait at least seven seconds, and then remove the earbuds. They will restart and automatically reconnect to your device.

If the issue persists follow the link to Perform a Factory Reset. Please note this will reset all setting of the buds back to factory settings.  

You can always Submit an Error Report through the Members App, if there is a software issue this will alert the developers to push out an update.  

The last option would be visiting an authorized service center for an evaluation of the device.

You can visit the link below to find a service center in your area or contact Samsung directly at 1-800-726-7864.
https://www.samsung.com/us/support/service/locations/

Please reach back out to let us know if any of this resolves the issue with your Galaxy Buds. 🙂