[Bug] K Pro series connect with BT 3.0 only (no BLE)

[bam80]

Describe the Bug

All the K Pro keyboard series are claimed to be BT 5.1 (so BLE) -capable.

Actually, they do connect with BT Classic (2.0/2.1) only:

$ sudo btmgmt con 
7C:1E:52:A8:89:77 type BR/EDR

Expected output:

$ sudo btmgmt con 
7C:1E:52:A8:89:77 type LE Random

Keyboard Used

K3 Pro, latest firmware (1.0.1)

Link to product page (if applicable)

No response

Operating System

Linux

qmk doctor Output

No response

Is AutoHotKey / Karabiner installed

• AutoHotKey (Windows)
• Karabiner (macOS)

Other keyboard-related software installed

No response

Additional Context

See also: #338

[JBertaux]

From the code (I looked only for K1 Pro) it looks BLE is not supported on the K1 Pro even though the product page mentions the opposite.

K1 Pro code executes ckbt51_init(false); here. In the header file ckbt51.h, there is a comment:

// Note: CKBT51 doesn't support BLE

I don't know if it's a mistake and the k1 pro should use BLE but this is a bit sad as the product page claims it is BT 5.1.

EDIT: From reading the Discord, it seems he Bluetooth module of the K series ckbt51 is not compatible with BLE.