Weird audio problems UR22C

[Elias Batek]

Occurs only with my audio interface Steinberg UR22C, which is connected via USB-C.

This is a regression.
Latest kernel known to work properly was: linux-image-5.4.0-48-generic.
(If I boot my current system with this one, everything's working fine.)

As far as I can tell this broke with vthe v5.4.0-51 update.

## Problem 1:
On reboot: after a few seconds playback stops (and freezes the application that was currently playing audio).

### For v5.4.0-56
This happens only once after each boot. Works fine after closing the hanging player.

### With v5.4.0-51
This used to occur again and again, plus the playback freeze was permanent.
Workaround: pulseaudio --kill +then: pulseaudio --start until the next freeze would happen)

### Characteristics
Audio would suddenly go completely silent.

## Problem 2:
Applies to v5.4.0-56
After starting some playback the first few seconds will also "contain" some unpleasant weird crackles.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-5.4.0-56-generic 5.4.0-56.62~18.04.1
ProcVersionSignature: Ubuntu 5.4.0-56.62~18.04.1-generic 5.4.73
Uname: Linux 5.4.0-56-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.20
Architecture: amd64
CurrentDesktop: Budgie:GNOME
Date: Sat Dec 12 00:59:47 2020
InstallationDate: Installed on 2018-10-20 (783 days ago)
InstallationMedia: Ubuntu-Budgie 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
SourcePackage: linux-signed-hwe-5.4
UpgradeStatus: No upgrade log present (probably fresh install)

[Elias Batek (0xeab)]

Update:
This time the playback freeze happened after an uptime of ~40min.
Did play audio almost right after logging in.

[Elias Batek (0xeab)]

Update II:
This used to occur again and again, plus the playback freeze was permanent.
^ also applies to v5.4.0-56