Hidden away in their FAQ (https://www.noterepeat.com/products/aka ... -questions) is the ugly truth:
It seems that Win 10 Developers Edition DOES support MIDI-over-Bluetooth.Why can't I connect my Windows computer to this device?
Transferring MIDI via Bluetooth LE is not officially supported. Although workarounds do exist, latency is typically a factor that adversely affects workflow. However, you can still certainly use this controller via wired USB connection with a PC running Windows OS.
I've contacted Akai and will update this thread if I find out more.
I've also tried using an USB extension cable, and bought a new one, as the supplied cable is ridiculously short (too short to be of any use to me) - but Windows fails to recognize the LPK25 when I do so.