RZ/G2UL Evaluation Board Kit Audio Issues

Hello!

I'm currently experimenting with the Evaluation Board RZ/G2UL and have encountered some issues with the audio functionality.

Here's my setup: I've connected a headset to the "Microphone in" and "Headphone out" jacks, and I've installed the RZ/G Verified Linux Package Version 3.0.3, which was built with Yocto. I've also added the pulseaudio recipe.

My problem is that when I use the aplay command to play an wav audio file, I only get white noise as output.
The used command was:
$> aplay -D default:CARD=rzssidaiwm8978h --channel=1 ~/test.wav

Here is some alsa background information:
$> aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
default:CARD=rzssidaiwm8978h
    rz-ssi-dai-wm8978-hifi,
    Default Audio Device
sysdefault:CARD=rzssidaiwm8978h
    rz-ssi-dai-wm8978-hifi,
    Default Audio Device


After running the aplay command, the white noise persists and a reboot is usually necessary to fix the issue.

However, I've discovered something interesting: if I start pulseaudio, I am able to play the audio file using paplay:
$> paplay -d alsa_output.platform-sound.analog-stereo ~/.baresip/sounds/error.wav

In order to make paplay work, I had to adjust the alsamixer settings as follows:
amixer sset 'Headphone' 100 on
amixer sset 'Speaker' 100 on
amixer sset 'PCM' 1000 on

Unfortunately, I haven't been able to get the microphone working. My approach was to try it with alsa record:

arecord -D default:CARD=rzssidaiwm8978h --channel=2 --format=S16_LE --rate=48000 test1.wav

I've also tried adjusting the alsamixer capture settings, but without any success. parecord also doesn't produce any useful output.

Has anyone else experienced this issue and found a solution?

Thank you in advance!