Ubuntu 20.04 では、どのデバイスでも Bluetooth が動作しなくなりました。以下のターミナル出力をご覧ください。
bluetooth.service - Bluetooth service
Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
Active: active (running) since Sat 2023-05-13 00:59:41 EDT; 1 weeks 5 days ago
Docs: man:bluetoothd(8)
Main PID: 2050 (bluetoothd)
Status: "Running"
Tasks: 1 (limit: 38205)
Memory: 4.6M
CGroup: /system.slice/bluetooth.service
└─2050 /usr/lib/bluetooth/bluetoothd
May 25 12:03:56 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:05:29 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:12:47 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:12:53 parmad-Precision-7720 bluetoothd[2050]: 30:D7:A1:B6:76:0E: error updating services: Host is down (112)
May 25 12:15:16 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:17:57 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:19:52 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:20:15 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:20:51 parmad-Precision-7720 bluetoothd[2050]: connect error: Host is down (112)
May 25 12:20:56 parmad-Precision-7720 bluetoothd[2050]: 30:D7:A1:B6:76:0E: error updating services: Host is down (112)