Apple MacBook Pro 16-inch Bluetooth is missing, will not pair or disconnects

The checks in more detail

The Pro's three Thunderbolt 4 ports and HDMI port feed docks and drives that can emit noise; a dock with a USB 3 hard drive beside the antenna area is a known cause of Bluetooth dropouts, so move the dock's cables away or use a longer cable. Keep the Mac away from other 2.4 GHz sources such as microwave ovens and some baby monitors. If AirPods jump to your iPhone, set Connect to This Mac in their settings to When Last Connected. Update the accessory's firmware, restart the Mac and update macOS.

If Bluetooth shows Not Available, shut the Mac down for thirty seconds and restart; there is no other reset. On a work Pro, a profile may limit Bluetooth accessories, which a company's administrator controls. If a particular accessory fails on all Macs, it is the accessory. If Bluetooth never works on the Pro after these steps, Apple Support can diagnose the hardware. Because a Pro is often used with an audio interface, a MIDI keyboard and wireless headphones, drivers for audio devices can conflict, so test with the audio device unplugged. Check the Audio MIDI Setup app in Utilities for devices that appear twice or aggregate devices that you made and forgot, since an aggregate device including a Bluetooth headset can make audio stutter.

Delete aggregate devices you no longer need, and the Bluetooth link becomes simpler and steadier. Keep the Mac's own Bluetooth menu uncluttered by removing devices that you no longer own: each paired device is a candidate for automatic connection, and an old speaker in the next room can grab the audio. Use the Option-click on the Bluetooth icon in the menu bar to see each device's firmware and battery; a device with an old firmware may need an update through its own app or a Mac utility from the maker, and the update often cures dropouts that no Mac setting can touch.