Questo è il comportamento previsto.
I dispositivi
BLE ( Bluetooth Low Energy ) non trasmettono sempre, come i dispositivi Bluetooth classici, rispondono a "pacchetti pubblicitari" inviati dal dispositivo di scansione (il tuo Mac).
BLE devices are detected through a procedure based on broadcasting
advertising packets. This is done using 3 separate channels
(frequencies), in order to reduce interference. The advertising device
sends a packet on at least one of these three channels, with a
repetition period called the advertising interval. For reducing the
chance of multiple consecutive collisions, a random delay of up to 10
milliseconds is added to each advertising interval. The scanner
listens to the channel for a duration called the scan window, which is
periodically repeated every scan interval.
Se tieni premuto Opzione mentre fai clic sull'icona Bluetooth, stai dicendo di "inviare i pacchetti pubblicitari per scoprire i dispositivi BLE".