iFixit Battery Capacity Dramatically Decreasing

I purchased a Macbook Air iFixit replacement battery about 240 days ago, and the charge capacity has dramatically decreased to 23.1% in recent weeks (based on CoconutBattery). I didn’t notice the battery being a significant issue until maybe a month ago - my guess is it’s gradually been decreasing - but now it holds at best an hour of charge and the service recommended status pops up. Any idea why this is happening and how to fix it?

EDIT: Added CoconutBattery screenshot