Plasma 5 update on Raspberry pi5 killed sound hdmi

Hi,

I have a Raspberry Pi5 with 8Gb and I installed Debian 12 with KDE Plasma on it.

Everything worked well and I could use my TV via HDMI as monitor and check on youtube and run any video without issue.

2 weeks ago KDE plasma released an update and since Pi5 has several issues:

  1. even if ORCA is disabled, Pi5 runs speech voice. To avoid it I had to uninstalled ORCA
  2. uninstalling ORCA remove HDMI output and replaced it with DUMMY OUTPUT
  3. now I have no sound on my TV as there is no more HDMI output, but also videos on youtube or any other info channel are slow and somehow stuttering.

If I use another DM on my Pi5 like the iOS default DM, videos are fluent and have no issues… except there is still no sound

so what should I do to get back sound and normal speed for video in Firefox ?

thx