Headphones Sony WH-1000XM4 don't work with 11.5.2

Hello ~ Take a look at info from Sony:

“Wireless Noise Canceling Stereo Headset

WH-1000XM4

Pairing and connecting with a computer (Mac)

The operation to register the device that you wish to connect to is called “pairing”. First, pair a device to use it with the headset for the first time. 

Compatible OS

macOS (version 10.10 or later)

Before starting the operation, make sure of the following: 

• Your computer has a Bluetooth function that supports music playback connections (A2DP). 
• When you use a video calling application on your computer, your computer has a Bluetooth function that supports calling connections (HFP/HSP). 
• The computer is placed within 1 m (3 feet) of the headset. 
• The headset is charged sufficiently. 
• The operating instructions of the computer is in hand. 
• Depending on the computer you are using, the built-in Bluetooth adaptor may need to be turned on. If you do not know how to turn on the Bluetooth adaptor or are unsure if your computer has a built-in Bluetoothadaptor, refer to the operating instructions supplied with the computer. 
• Set the computer speaker to the ON mode.  
• If the computer speaker is set to the  “OFF” mode, no sound is heard from the headset. 
• 
  
• Computer speaker in the ON mode
• 

1. Enter pairing mode on this headset. 
2. Turn on the headset when you pair the headset with a device for the first time after you bought it or after you initialized the headset (the headset has no pairing information). The headset enters pairing mode automatically. In this case, proceed to step  . 
3. When you pair a second or subsequent device (the headset has pairing information for other devices), press and hold the  (power) button for about 7 seconds. 
4. 
5. Check that the indicator (blue) repeatedly flashes twice in a row. You will hear the voice guidance say, “Bluetooth pairing”. 
6. 
7. Wake the computer up if the computer is in standby (sleep) or hibernation mode. 
8. Register the headset using the computer. 
9. Select [  (System Preferences)] - [Bluetooth] from the task bar in the lower right part of the screen. 
   1. 
10. Select [WH-1000XM4] of the [Bluetooth] screen and click [Connect]. 
11. If [WH-1000XM4] and [LE_WH-1000XM4] are displayed, select [WH-1000XM4]. 
12. [LE_WH-1000XM4] will be displayed first, but wait until [WH-1000XM4] is displayed. 
13. It may take about 30 seconds to 1 minute for [WH-1000XM4] to be displayed. 
14. If [WH-1000XM4] is not displayed, try again from step  . 
    1. 
15. If Passkey (*) input is required, input “0000”. 
16. The headset and computer are paired and connected with each other. You will hear the voice guidance say, “Bluetooth connected”. 
17. If they are not connected, see “Connecting to a paired computer (Mac)”. 
18. *
19. A Passkey may be called “Passcode”, “PIN code”, “PIN number”, or “Password”. 
20. Click the speaker icon in the upper right part of the screen and select [WH-1000XM4]. 
21. Now you are ready to enjoy music playback on your computer. 
22. 

Hint

• The operation above is an example. For more details, refer to the operating instructions supplied with the computer. 
• To delete all Bluetooth pairing information, see “Initializing the headset to restore factory settings”. 

Note

• If pairing is not established within 5 minutes, pairing mode is canceled. In this case, start the operation again from step  . 
• Once Bluetooth devices are paired, there is no need to pair them again, except in the following cases: 
  • Pairing information has been deleted after repair, etc. 
• When a 9th device is paired. 
  • The headset can be paired with up to 8 devices. If a new device is paired after 8 devices are already paired, the registration information of the paired device with the oldest connection date is overwritten with the information for the new device. 
  • When the pairing information for the headset has been deleted from the Bluetooth device. 
• When the headset is initialized. 
  • All of the pairing information is deleted. In this case, delete the pairing information for the headset from the device and then pair them again. 
• The headset can be paired with multiple devices, but can only play music from 1 paired device at a time.”

~Katana-San~

macOS 11.5.2. Sony WH-1000XM4 -> "Power on … Bluetooth connected." Apple Music is playing fine on my M1 mac mini. Keyboard volume controls work just fine on Magic Keyboard extended.

Power off your headphones. Visit System Preferences > Bluetooth Preferences. Select the WH-1000XM4 entry, right-click on it, and choose Remove. Restart your Mac, and reopen the Bluetooth Preferences. Power on your headphones and proceed with the pairing process.

Note: I have not used the Sony iPhone application to tweak these headphones, and they are not paired to another device (support for up to two devices).

Hello again ~ I thought you most probably had tried that but thought to post and perhaps help. One of the great things about this forum … so many smart and dedicated people who are always willing to help out. I hope the excellent post by * VikingOSX * who by the way is one of those smart and dedicated people answered your question. Post back and let us know and I hope you are enjoying your headphones again soon:)

~Katana-San~

Hello Javier ~ I am so glad for you. Good work .Come back to the forum and start helping others yourself. Enjoy your headphones:)

~Katana-San~