There are many possibilities.
Leds aren’t always accurate on electronics. But yes,that sounds extreme. It could be as simple as a bad battery. It could be a bad charger as well. I’d not those 2 things,it’s the circuitry. It could be a component issue.
If the battery life is fine,but just an inaccurate indication of battery,it could also be a faulty battery meter.
Sometimes charging until it won’t charge(keep it plugged in for a while after it hits 4th led or appears to stop charging),then drain it until it shuts off,then repeat the full charge step. In many devices,this calibrates the software meter for the battery,to make it more accurate.
have you tried using it for a while at a time? Is the battery life ok,setting aside the meter?
worse case,you could return it as defective,right? Just swap it out?