Hardwired doorbell shown as solar connected

Hi, I'm having a doorbell 3 plus and hardwired in-home chime. It used to work well and was able to get charged by it when the battery level drops below 90%. However recently, it's not showing hardwired but solar connected. Apparently, it's not being charged now. I try to reset my doorbell but nothing changed. Even if I shut down the in home chime, it's still showing as solar connected. Could any point me what's the next? Thanks!