Describe the bug
When playing some streams on the Thinkpad X1 Carbon 7th, the volume level is noticeably (~50%?) lower for the first ~0.5s.

To Reproduce
I can hear it by playing the following sample via aplay:
aplay -Dhw:0,0 output.wav
The second bell ring sounds louder. Opening the file in ex. audacity shows that in fact the two bell rings are of the same amplitude.

Reproduction Rate
Reproduces all the time when playing directly through alsa.
Results are mixed when playing through pulseaudio. The volume step up is sometimes there, sometimes not; I don't know why.
It seems to me that this occurs more frequently with sof firmware v1.5 than v1.4.3 but when alternating between the two by changing the files under /lib/firmware and unloading/reloading kernel modules, I can sometimes reproduce the issue with v1.4.3 as well. v1.5.1 is the same as v1.5 in this regard (also bad).
This seems to occur regardless of mixer levels.
It occurs in headphones and speakers.

Expected behavior
Constant sound level.

Impact
annoyance, in daily use it doesn't seem to occur with pulseaudio output if I boot with v1.4.3 sof firmware and don't touch it afterwards.

Environment

1. Branch name and commit hash of the 2 repositories: sof (firmware/topology) and linux (kernel driver).

   • Kernel: Debian unstable 5.6.0-2-amd64
   • SOF: stable-v1.4.3/stable-v1.5.1 (from sof-bin repository)

2. Name of the topology file

   • Topology: sof-tplg/sof-hda-generic-4ch.tplg sof/sof-cnl.ri

3. Name of the platform(s) on which the bug is observed.

   • Platform: Realtek ALC285 vendor 0x10ec0285 codec SSID 0x17aa2293