HELP! Left Airpod battery indicator is always at 100% even I know it's not

My left Airpod 2 says that it's always at 100%, even when I take them out of the case. The right pod's indicator is fine, but the left is always at 100 regardless. Say I use both pods for around 4 hours. The right one will say like 30%, while the left will still tell me it's at 100. What can I do to fix this? I've tried re-pairing them.

I also feel like it's worth mentioning that when I take the left pod out of the case after a full charge, a red exclamation mark shows up beside it (on the menu that appears on your phone when you open your Airpods case)

Please help!