Zorin OS（基于Ubuntu 20）蓝牙键盘配对连接成功但无法输入的问题求助

大家好，我遇到了一个棘手的蓝牙键盘问题，想请教下有没有朋友能帮忙分析解决：

我的笔记本装了三个系统：Zorin OS（基于Ubuntu 20）、Garuda Linux和Windows。这款罗技K480蓝牙键盘我用了挺久，在Windows和Garuda里表现都正常：

• 同一个系统下，关机重启后键盘会自动连接，不用手动操作；
• 跨系统启动的话，比如从Windows切到Garuda，需要先忘记蓝牙设备再重新配对（配对时会要求输入6位验证码），但配对完成后就能正常打字。

但Zorin OS这边一直有点异常：每次我进入Zorin都得重新配对键盘，而且从来没弹出过要求输入6位验证码的提示，不过之前配对后至少还能正常输入。

结果今天问题升级了：我像往常一样尝试连接键盘，GUI明明显示连接成功，但键盘完全没法输入任何内容。我重启了笔记本，问题依旧；切换到Windows和Garuda，键盘又能正常工作，说明硬件本身没问题。

我试着用终端操作蓝牙，步骤和输出如下：
先重启蓝牙适配器：

lockrr@lockrr-Lenovo-YOGA-910-13IKB:~$ sudo hciconfig  hci0 down
lockrr@lockrr-Lenovo-YOGA-910-13IKB:~$ sudo hciconfig  hci0 up
lockrr@lockrr-Lenovo-YOGA-910-13IKB:~$ sudo hciconfig  hci0 reset

然后用bluetoothctl操作：

lockrr@lockrr-Lenovo-YOGA-910-13IKB:~$ bluetoothctl
Agent registered
[bluetooth]# devices
Device EC:2E:98:61:78:2C LAPTOP-UTURCPFT
Device 5B:E7:23:A2:0C:C7 5B-E7-23-A2-0C-C7
Device 74:60:9A:61:3A:75 74-60-9A-61-3A-75
Device 6D:5E:DC:CC:2D:76 6D-5E-DC-CC-2D-76
Device F0:B0:40:89:C1:82 MiTVStick
Device 41:42:E5:85:B4:07 SOUNDBOX LITE
[bluetooth]# scan on
Discovery started
[CHG] Controller 58:00:E3:CF:1B:AA Discovering: yes
[CHG] Device 6D:5E:DC:CC:2D:76 RSSI: -69
[CHG] Device 6D:5E:DC:CC:2D:76 TxPower: 12
[NEW] Device 34:88:5D:39:97:F5 Logitech Keyboard K480
[CHG] Device EC:2E:98:61:78:2C RSSI: -75
[CHG] Device 74:60:9A:61:3A:75 RSSI: -67
[CHG] Device 5B:E7:23:A2:0C:C7 RSSI: -79
[CHG] Device 5B:E7:23:A2:0C:C7 TxPower: 8
[NEW] Device 4F:2E:44:30:09:E0 4F-2E-44-30-09-E0
[bluetooth]# pair 34:88:5D:39:97:F5
Attempting to pair with 34:88:5D:39:97:F5
Failed to pair: org.bluez.Error.AlreadyExists
[bluetooth]# trust 34:88:5D:39:97:F5
[CHG] Device 34:88:5D:39:97:F5 Trusted: yes
Changing 34:88:5D:39:97:F5 trust succeeded
[CHG] Device EC:2E:98:61:78:2C TxPower: 10
[CHG] Device F0:B0:40:89:C1:82 RSSI: -72
[CHG] Device 74:60:9A:61:3A:75 RSSI: -75
[bluetooth]# connect 34:88:5D:39:97:F5
Attempting to connect to 34:88:5D:39:97:F5
[CHG] Device 34:88:5D:39:97:F5 Connected: yes
[CHG] Device 34:88:5D:39:97:F5 Modalias: usb:v046DpB330d2800
[CHG] Device 34:88:5D:39:97:F5 UUIDs: 00001000-0000-1000-8000-00805f9b34fb
[CHG] Device 34:88:5D:39:97:F5 UUIDs: 00001124-0000-1000-8000-00805f9b34fb
[CHG] Device 34:88:5D:39:97:F5 UUIDs: 00001200-0000-1000-8000-00805f9b34fb
[CHG] Device 34:88:5D:39:97:F5 ServicesResolved: yes
Connection successful
[CHG] Device 74:60:9A:61:3A:75 RSSI: -67
[CHG] Device 74:60:9A:61:3A:75 RSSI: -76
[CHG] Device 74:60:9A:61:3A:75 RSSI: -66
[CHG] Device 6D:5E:DC:CC:2D:76 RSSI: -77
[CHG] Device 74:60:9A:61:3A:75 RSSI: -74
[NEW] Device EC:2E:98:89:C1:82 EC-2E-98-89-C1-82
[Logitech Keyboard K480]#

看起来连接流程是成功的，但键盘还是没法输入。我怀疑有进程或设置阻塞了蓝牙，用rfkill检查了一下，所有设备都没有软/硬阻塞：

lockrr@lockrr-Lenovo-YOGA-910-13IKB:~$ rfkill list all
0: ideapad_wlan: Wireless LAN
Soft blocked: no
Hard blocked: no
1: ideapad_bluetooth: Bluetooth
Soft blocked: no
Hard blocked: no
2: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
3: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no

有没有朋友知道这可能是什么问题？麻烦帮忙出出主意，谢谢了！

备注：内容来源于stack exchange，提问作者Flitzcore