Cannot receive or send SMS

[aur3l14no]

Environment

Hardware and OS: M1, Big Sur 11.4
Smartphone: OnePlus (Android 11)

Problem

Can't receive or send SMS.

I changed verbosity to 5 and checked the log file. Nothing shows up when I receive SMS. And whenever I send SMS, there is a log but nothing actually happens.

Debug | send(:{
  "id" : 13,
  "type" : "kdeconnect.sms.request",
  "body" : {
    "sendSms" : true,
    "phoneNumber" : "_________",
    "messageBody" : "Why Keep Failing!\n"
  }
}
 whenCompleted:nil) [<Connection:__________________>]

I'm able to check sms using KDEConnect from https://binary-factory.kde.org/view/MacOS/job/kdeconnect-kde_Release_macos/ , so I guess it's not a problem on the smartphone end.