Ubuntu – Xubuntu only shows Dumthe output for audio unless I plug in a hdmi, then I can use the hdmi audio

I have a Dell G3 15. Running Xubuntu 18.04. Everything was working perfectly until the 26/27th February 2020. After this the audio stopped working and I only see a dummy output in the mixer. Im guessing there was an update at this time. I think the Laptop has a ALC3204 sound card. I found that if I plug in a hdmi display I can play audio through the hdmi.

Things I have tried:

• Reinstalled Pulse Audio and rebooted.
• Disabled Secure Boot.
• Opened the terminal and ran sudo apt-get install pavucontrol pavucontrol then entered configuration profile to set configuration to analog stereo out, only to find "dummy output" as the only option again.
• Opened the terminal and ran sudo alsa force-reload.
• pulseaudio -k && sudo alsa force-reload had no effect.
• BIOS -> disable audio -> boot to Ubuntu -> restart -> BIOS -> enable audio -> boot to Ubuntu did not work. I still have "Dummy output" as the only sound output option.
• I went onto the dell site to see if I could download a new driver for the Realtek ALC3204 but the only drivers that I could find on the site are only for Windows 10.
• added "options snd-hda-intel model=headset-mic probe_mask=0x103" to /etc/modprobe.d/alsa-base.conf , btw this stops the hdmi audio working after a restart. So if i do this I have no audio no matter what I do.
• I tried a USB audio "card" it works fine.
• I just added, snd_hda_intel.dmic_detect=0 to this line GRUB_CMDLINE_LINUX_DEFAULT="quiet splash mem_sleep_default=deep" in /etc/default/grub then ran update-grub and restarted. the headphone jack now works, speaker and mic still don't work.

Some outputs

G3-3590:~$ aplay -L
default
    Playback/recording through the PulseAudio sound server
null
    Discard all samples (playback) or generate zero samples (capture)
pulse
    PulseAudio Sound Server
hdmi:CARD=NVidia,DEV=0
    HDA NVidia, HDMI 0
    HDMI Audio Output
dmix:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Direct sample mixing device
dsnoop:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Direct sample snooping device
hw:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Direct hardware device without any conversions
plughw:CARD=NVidia,DEV=3
    HDA NVidia, HDMI 0
    Hardware device with all software conversions

G3-3590:~$ sudo inxi -Fxz
System:    Host: plakkies-G3-3590 Kernel: 5.3.0-46-generic x86_64
           bits: 64 gcc: 7.5.0
           Desktop: Xfce 4.12.3 (Gtk 2.24.31) Distro: Ubuntu 18.04.4 LTS
Machine:   Device: laptop System: Dell product: G3 3590 serial: <filter>
           Mobo: Dell model: 061RYD v: A00 serial: <filter>
           UEFI: Dell v: 1.6.0 date: 08/08/2019
Battery    BAT0: charge: 46.1 Wh 100.0% condition: 46.1/51.0 Wh (90%)
           model: LGC-LGC4.474 DELL 415CG98 status: Full
CPU:       6 core Intel Core i7-9750H (-MT-MCP-) 
           arch: Skylake rev.10 cache: 12288 KB
           flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 31199
           clock speeds: max: 4500 MHz 1: 1370 MHz 2: 3619 MHz 3: 4391 MHz
           4: 3604 MHz 5: 3808 MHz 6: 3193 MHz 7: 4152 MHz 8: 3590 MHz
           9: 3847 MHz 10: 3612 MHz 11: 3615 MHz 12: 3585 MHz
Graphics:  Card-1: Intel Device 3e9b bus-ID: 00:02.0
           Card-2: NVIDIA Device 2191 bus-ID: 01:00.0
           Display Server: X.Org 1.20.5
           drivers: modesetting,nvidia (unloaded: fbdev,vesa,nouveau)
           Resolution: 1920x1080@60.00hz
           OpenGL: renderer: GeForce GTX 1660 Ti with Max-Q Design/PCIe/SSE2
           version: 4.6.0 NVIDIA 435.21 Direct Render: Yes
Audio:     Card-1 Intel Cannon Lake PCH cAVS
           driver: sof-audio-pci bus-ID: 00:1f.3
           Card-2 NVIDIA Device 1aeb driver: snd_hda_intel bus-ID: 01:00.1
           Sound: Advanced Linux Sound Architecture v: k5.3.0-46-generic

G3-3590:~$ dmesg |grep audio
[    3.555373] snd_hda_intel 0000:01:00.1: Handle vga_switcheroo audio client
[    3.640969] sof-audio-pci 0000:00:1f.3: warning: No matching ASoC machine driver found
[    3.640974] sof-audio-pci 0000:00:1f.3: DSP detected with PCI class/subclass/prog-if 0x040100
[    3.641097] sof-audio-pci 0000:00:1f.3: use msi interrupt mode
[    3.645485] sof-audio-pci 0000:00:1f.3: bound 0000:00:02.0 (ops i915_audio_component_bind_ops [i915])
[    3.649680] sof-audio-pci 0000:00:1f.3: hda codecs found, mask 5
[    3.649682] sof-audio-pci 0000:00:1f.3: using HDA machine driver skl_hda_dsp_generic now
[    3.701574] sof-audio-pci 0000:00:1f.3: Direct firmware load for intel/sof/sof-cfl.ri failed with error -2
[    3.701577] sof-audio-pci 0000:00:1f.3: error: request firmware intel/sof/sof-cfl.ri failed err: -2
[    3.701580] sof-audio-pci 0000:00:1f.3: error: failed to load DSP firmware -2
[    3.701945] sof-audio-pci 0000:00:1f.3: error: sof_probe_work failed err: -2
[    3.925713] snd_hda_codec_generic hdaudioC0D0: autoconfig for Generic: line_outs=0 (0x0/0x0/0x0/0x0/0x0) type:line
[    3.925716] snd_hda_codec_generic hdaudioC0D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[    3.925717] snd_hda_codec_generic hdaudioC0D0:    hp_outs=0 (0x0/0x0/0x0/0x0/0x0)
[    3.925717] snd_hda_codec_generic hdaudioC0D0:    mono: mono_out=0x0
[    3.925718] snd_hda_codec_generic hdaudioC0D0:    dig-out=0x7/0x0
[    3.925718] snd_hda_codec_generic hdaudioC0D0:    inputs:
[    4.755902] usbcore: registered new interface driver snd-usb-audio

Thanks for any help you can provide.