I’m playing with a Korg MicroKey Air which connects ok via Bluetooth. If it goes out of range, or I switch the microkey off and back on, then I have to use the power button on C3 to re-recognise it. This does not happen with USB MIDI devices - I can disconnect and reconnect those at will, and C3 picks it back up straight away.
Probably a question for the keyboard manufacturer but my guess is the keyboard goes out of range, the driver loses it’s connection and doesn’t recover. Because the MIDI device isn’t disappearing/reappearing in the list of devices reported by Windows Cantabile is blissfully unaware and doesn’t try to reconnect it - cause it thinks it’s still there.