I have seen many threads about buds+ acting dead on one side only etc, this happened to me a few months ago where the case would show green, but only one of them connected to my phone, the other appeared dead.
The solution that worked for me at the time was to remove the charging bud and then insert it to charge again, this would be repeated multiple times until randomly it would start charging properly again.
More recently this method stopped working and I tried the alternative method of pressing down the touch button whilst in the case hoping to reset it but that never worked.
I ended up taking it to Samsung who after a few hours had repaired them, they reported back saying that it was a software problem with the earbud itself and not anything hardware related. I thought it was a dead battery or connector not working etc but they used their machines to reset the firmware and it's all working again now.
- faulty earbuds