Cant connect to bluetooth headphones [contains lots of terminal outputs to help debug]

I have the Sennheiser pxc550-ii bluetooth headphones that I want to pair with my Ubuntu 20.04 desktop and have aptx-hd and aptx-ll codecs working. Its worth noting regarding the latter that I've installed this ppa. Its also worth noting that I can pair using bt to my bt speakers just fine.

I've tried using the default bloothtooth tool as well as blueman-manager. In both I can see the headphones in the list of available bluetooth devices, but both just fail to pair.

Then I turned to following this guide, the output of the commands they suggest are:

1st command:

jam@jam-ncase:~$ lsmod | grep bluetooth
bluetooth             454656  49 btrtl,btintel,btbcm,bnep,btusb,rfcomm
ecdh_generic           16384  2 bluetooth
rfkill                 28672  11 asus_wmi,bluetooth,cfg80211
crc16                  16384  2 bluetooth,ext4

2nd command:

jam@jam-ncase:~$ dmesg | grep Bluetooth
[    2.285152] Bluetooth: Core ver 2.22
[    2.285162] Bluetooth: HCI device and connection manager initialized
[    2.285165] Bluetooth: HCI socket layer initialized
[    2.285166] Bluetooth: L2CAP socket layer initialized
[    2.285168] Bluetooth: SCO socket layer initialized
[    2.302897] Bluetooth: hci0: read Intel version: 3707100180012d0d2a
[    2.302898] Bluetooth: hci0: Intel device is already patched. patch num: 2a
[    2.354229] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[    2.354230] Bluetooth: BNEP filters: protocol multicast
[    2.354232] Bluetooth: BNEP socket layer initialized
[    6.314639] Bluetooth: RFCOMM TTY layer initialized
[    6.314643] Bluetooth: RFCOMM socket layer initialized
[    6.314646] Bluetooth: RFCOMM ver 1.11

3rd command:

● bluetooth.service - Bluetooth service
     Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
     Active: active (running) since Wed 2020-08-26 09:01:38 BST; 5min ago
       Docs: man:bluetoothd(8)
   Main PID: 6075 (bluetoothd)
     Status: "Running"
      Tasks: 1 (limit: 19076)
     Memory: 1.9M
     CGroup: /system.slice/bluetooth.service
             └─6075 /usr/lib/bluetooth/bluetoothd

Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Bluetooth management interface 1.16 initialized
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSource/VENDOR/LDAC
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSource/VENDOR/APTXHD
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSource/VENDOR/APTX
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSource/AAC
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSource/SBC
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSink/VENDOR/APTXHD
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSink/VENDOR/APTX
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSink/AAC
Aug 26 09:01:38 jam-ncase bluetoothd[6075]: Endpoint registered: sender=:1.47 path=/MediaEndpoint/A2DPSink/SBC

4th:

jam@jam-ncase:~$ rfkill list
0: phy0: Wireless LAN
    Soft blocked: no
    Hard blocked: no
1: hci0: Bluetooth
    Soft blocked: no
    Hard blocked: no

I've noticed this error message as well:

jam@jam-ncase:~$ pactl load-module module-bluetooth-discover
Failure: Module initialisation failed

The terminal output when I try and pair/connect can be found here.One line that stands out from that file is this one:

> HCI Event: Disconnect Complete (0x05) plen 4             #56 [hci0] 25.099314
        Status: Success (0x00)
        Handle: 256
        Reason: Remote Device Terminated due to Power Off (0x15)

My headphones are definitely power on though. Would someone be able to advise on how I should try and fix this?