Give these guides a try and let us know if the issue is helped by them:
Some common troubleshooting for this type of issue is cleaning the pins / case with alcohol, trying a different charger, base and outlet, and resetting the earbuds.
Still need help? You may need to contact Samsung Support for assistance:
Inside the US? --> https://www.samsung.com/us/support/contact/
Outside the US? --> https://www.samsung.com/us/common/visitlocationsite.html