No sound thrue HDMI over PBP dock

Describe your issue

When PPP EE connected to PBPDock no hdmi sound interface are detected. (only the jack sound interface)

Expected Behavior

plugin HDMI TV then play videos result in image and sound shared thrue the HDMI port.

Observed Behavior

no HDMI sound interface detected

How reproducible is the bug?

Always

Steps to reproduce the bug

1. plugin HDMI TV
2. play movie
3. watch and hear the movie

What device are you using?

PPP EE Linux phone 6.0-rockchip #1 (closed) SMP PREEMPT_DYNAMIC Mon Nov 14 16:46:46 UTC 2022 aarch64 GNU/Linux

Distributor ID: Debian Description: Debian GNU/Linux bookworm/sid Release: testing Codename: bookworm

Which mobian repository are you using?

deb https://repo.mobian.org/ staging main non-free

How did you get your Mobian Image?

• calamares installer