I'm having the same issue, I can charge the battery but in my opinion the bike should be charging the battery. Makes me nervous to go far like this.
I can charge mine to full charge, drive it for 15 or 20 minutes come back put the charger on it and it says it's at 80% - Not a great feeling.
First noted the issue second time I drove it, stopped on the trail to do a uturn. Suddenly I had zero throttle response, then I shut it off and click click click. miles from home.
Going to buy a new battery for this thing and it better not let me down again or CFMoto won't like me much. 2 year old bike with a charging issue