Ubuntu 22.04 - Sound plays only as root user (RME RayDAT ALSA device not visible in Pulseaudio)

I have installed the latest Ubuntu 22.04.1 LTS with 4 audio devices:

alex@gamma:~$ hdspconf
...
Looking for HDSP cards :
Card 0 : RME RayDAT S/N 0xc36b4a at 0xfb300000, irq 24
Card 1 : HDA Intel PCH at 0xfbe00000 irq 75
Card 2 : HDA NVidia at 0xfb080000 irq 76
Card 3 : Logitech Logitech G933 Gaming Wireless H at usb-0000:00:1a.0-1.2, full speed
No Hammerfall DSP card found.

• Card 0 is what I want to get to work as my default system device for e.g. VLC, Chrome, Youtube, etc. It is an PCIe device.
• Card 1 is an onboard device that I don't use.
• Card 3 is my screen, and working fine, but the sound is cheap.
• Card 4 is my headset, and working fine.

A complete config dump of alsa-info can be found here: alsa-info

In Gnome Sound Settings I can see these devices: Sound Settings, where:

• HDMI/DisplayPort-HD-NVidia -> is the screen (Card 2) (working fine)
• Digital Output (S/PDIF)-Built-in Audio -> I am 99% sure this is the onboard device (Card 1) (unused)
• Digital Output (S/PDIF)-G933 Wireless Headset... -> is the headset (Card 3) (working fine)
• Analog Aoutput -G933 Wireless Headset... -> is also the headset (Card 3) (also working fine)

What I am painfully missing here is the Card 0 : RME RayDAT.

When I play a test sound with alsa, then I hear nothing, but I see the Alsa plug-in [aplay] is popping up for a short time in the Gnome Sound Settings: Alsa plug-in aplay:

aplay /usr/share/sounds/alsa/Front_Center.wav

When I play the same test sound root, I can hear it on my RME RayDAT device perfectly:

sudo aplay /usr/share/sounds/alsa/Front_Center.wav

From here I tried alot of stuff from the internet, but nothing was working and I rolled back all of them, because it seemed these advices were for older Version of Ubuntu.

Most senseful advices were to put my user into audio and pulse groups which had no effect:

alex@gamma:~$ cat /etc/group | grep "audio"
audio:x:29:pulse,alex,pulseaudio
pulse-access:x:124:alex,pulseaudio,root

alex@gamma:~$ cat /etc/group | grep "pulse"
audio:x:29:pulse,alex,pulseaudio
pulse:x:123:alex
pulse-access:x:124:alex,pulseaudio,root

Here is more maybe useful diagnose output:

alex@gamma:~$ cat /proc/asound/cards 
 0 [HDSPMxc36b4a   ]: HDSPM - RME RayDAT_c36b4a
                      RME RayDAT S/N 0xc36b4a at 0xfb300000, irq 24
 1 [PCH            ]: HDA-Intel - HDA Intel PCH
                      HDA Intel PCH at 0xfbe00000 irq 75
 2 [NVidia         ]: HDA-Intel - HDA NVidia
                      HDA NVidia at 0xfb080000 irq 76
 3 [H              ]: USB-Audio - Logitech G933 Gaming Wireless H
                      Logitech Logitech G933 Gaming Wireless H at usb-0000:00:1a.0-1.2, full speed

It would be really cool if you can help me with to fix this issue. Thank you in advance!

Finally I did not solve the problem, but I got rid of it by simply upgrading to Ubuntu 20.10 wich comes with the new sound architecture "PipeWire", wich seems to address exactly these kind of problems with professional sound devices.

I now see the RME RayDat in general system settings by default, and can use hdspmixer to arrange submixes and routings, so that casual appication sound goes to the digital AES output of the RayDAT.

The major drawback of this approach is that I lost the LTS long term support.