Bluetooth headset related info:
https://wiki.archlinux.org/index.php/Bluetooth_headset#Connecting_works.2C_but_I_cannot_play_sound
https://wiki.archlinux.org/index.php/Bluetooth_headset
https://wiki.archlinux.org/index.php/Bluetooth_headset#Gnome_with_GDM
https://wiki.archlinux.org/index.php/Talk:Bluetooth_headset#GDMs_pulseaudio_instance_captures_bluetooth_headset
https://bbs.archlinux.org/viewtopic.php?id=194006
Test the linux, linux-hardened, and linux-mainline kernels (and headers).
sudo pacman -S linux linux-headers
sudo pacman -S linux-mainline linux-mainline-headers
sudo pacman -S linux-hardened linux-hardened-headers
Reboot.
Swap kernels at the grub advanced boot menu.
From the ArchWiki:
Headset via Pipewire
PipeWire acts as a drop-in replacement for PulseAudio and offers an easy way to set up Bluetooth headsets. It includes out-of-the-box support for A2DP sink profiles using SBC/SBC-XQ, AptX, LDAC or AAC codecs, and HFP/HSP.
Install pipewire-pulse (which replaces pulseaudio and pulseaudio-bluetooth).
The daemon will be started automatically as a user service. Use pavucontrol or your desktop environment's settings for configuration. For more information, see PipeWire#Bluetooth devices.
Also, be sure to add the following setting, if it isn't already present in /etc/bluetooth/main.conf.
Add the following near the bottom in the [Policy] section:
[Policy]
AutoEnable=true
Unpair the headset, then restart the bluetooth service:
systemctl restart bluetooth
Pair your headset again, and connect to it.
Check which Bluetooth packages are installed:
pacman -Q | grep blue
Please post the output.