Hey there, sorry to hear you're stuck with this frustrating Bluetooth headset problem! Since you've already tried removing and re-pairing the headset, let's walk through some deeper fixes tailored to your High Sierra system:

• Reset the Bluetooth Module
  This is often the quickest fix for glitches. Here are two ways to do it:

  1. Graphical method: Hold down Shift + Option and click the Bluetooth icon in your menu bar. You'll see an expanded menu—select "Reset Bluetooth module".
  2. Terminal method: Open Terminal (found in Applications > Utilities), run this command:

     sudo pkill bluetoothd
     

     When prompted, enter your admin password (note: it won't show up as you type, that's normal). This restarts the core Bluetooth service.

• Delete Corrupted Bluetooth Preference Files
  Damaged preference files can cause persistent pairing or audio issues:

  1. Turn off Bluetooth from your menu bar first.
  2. Open Finder, press Cmd + Shift + G, and paste ~/Library/Preferences/ into the dialog box to jump to the folder.
  3. Locate and delete these two files:
     • com.apple.Bluetooth.plist
     • com.apple.Bluetooth.plist.lockfile
  4. Restart your MacBook Air, then re-pair your headset from scratch.

• Cut Down Wireless Interference
  Bluetooth uses the 2.4GHz frequency, which clashes with many WiFi networks and other Bluetooth devices. Try these tweaks:

  • If your router supports it, switch your WiFi to the 5GHz band (this won't interfere with Bluetooth signals).
  • Turn off any unused Bluetooth devices nearby (like mice, keyboards, or speakers) to free up bandwidth.
  • Move your MacBook away from routers, microwaves, or other electronics that emit strong wireless signals.

• Reset the SMC (System Management Controller)
  The SMC handles low-level hardware functions like Bluetooth power. For non-Touch Bar MacBook Air models (which run High Sierra), follow these steps:

  1. Shut down your MacBook completely.
  2. Hold down Shift + Control + Option and press the power button at the same time. Keep all four keys held for 10 seconds.
  3. Release the keys, then press the power button again to turn on your Mac.

• Check for Final High Sierra Updates
  While High Sierra is no longer actively supported by Apple, there might be a late security patch that includes Bluetooth fixes. Open the App Store, click the Updates tab, and install any available system updates (if there are any).

Since your headset works perfectly on other Macs, these steps should target the specific issue with your MacBook Air's Bluetooth setup. Let me know if any of these resolve the problem!

内容的提问来源于stack exchange，提问作者valentina.a87