Soundcore Liberty 3 Pro (Earbuds don't charge in the box)

Hi, I purchased the pair around 2 years ago. I don’t use the earbuds quite often. Most of time when I use them I don’t use it single. I use both when listening to music. Just wanted to know why don’t they charge when put in the case. As I was so worried thinking what happened even without using them. Would appreciate any help from the team as I really love these earbuds. They do a lot for the price point, I don’t wanna lose 'em. I hope there’s a fix for this. ( Right ear works but not the Left side) I Just Wanna know that whether this is fixable or not as i saw many other people facing this issue on YouTube but none has found a solution to it. I tried everything which was suggested to do if it doesn’t charge in the case but sadly it didn’t work. i suspect that it should be that the battery might have diminished. I know nothing about repairing these type of stuff. I hope it shouldn’t be the battery which is dead. Please Soundcore HELP ME OUT.