I have read various threads where these don’t have a very long batter life. Unfortunately, its not there’s anything wrong, its that they were manufactured this way. I regret buying them. The case works well, the headphones work well but they charge and don’t last more than 20 minutes. Go buy Samsung’s new Buds+. They might be pricey, but they are worth it.
Sounds like you have either knockoffs or defective ones. I have these and mine last me my whole 8 hour shift at work
Seems a defective item.
You should contact the service for further help