You could try it with the PulseAudio Control tool. It is a Program to set up Audio Output and Input. You can install it with the Terminal Command sudo apt install pavucontrol
It doesn't have Power Saving Settings. It is only for set up Your Audio. Go to the Output Tab and choose Your Audio Output. And click on the Marker. And then test if it works. Because of my Theme the UI maybe doesn't look like yours, but as an Example it should be enough:
that's my view but i still do not know how this can help me with the sound delay after a period of idle time?
When i click onto the tag the background becomes dark grey - seems to be activated. But never the less after a very short period i change my loudness and for several seconds nothing occurs - after 2-3 seconds i hear the loudness changing ....
That looks okay. Could it be ... do Your system run in Wayland or Xorg? To check that, go to Settings>About (in German ''Info'') and there look for ''Window Manager'' (Fenstermanager).
Wayland, okay. Let's try to change to Xorg. To do that, go to the Login Screen and click on Your Profile so that the Password Field appears. It has to be appeared! when it is appeared, You should see in the bottom right Corner a Gear Icon. Click on it. Then you should see 2 Options. Choose the Option ''Zorin Desktop on Xorg'' and login and check if it works.
Okay, let's go a Step back ... What is with the Cable that You use? Could it be that it is broken? Can You test it with another Cable on another HDMI Port (PC and Monitor) - if other Ports are available.
Sometimes the Ghost in the Machine is a bit ... pecular.
good idea, have read this in other forums as well ...
... but i have to say sorry, the sound is "fading" after some moments.
Playing e.g. Solitaire does not "produce enough sounds in a couple of times" to make the power_save ending and making "clicks of moving cards" hearable.
Switching to e.g. youtube -> starting a video -> the sound comes up after a few seconds. During a running video -> playing solitaire => all clicks / card movements are hearable.
So as long as the sound has "work to do" the hdmi sound behaves as expected.
I have only one HDMI port at the notebook but 2 at the monitor. Tested both -> no difference. Have also several HDMi cables also with High Speed plus Ethernet support etc. -> nothing different so far.
So seems a "config" or "setting" is still needed to switch OFF the power_save mode permanently.
Hmm ... tricky. The only other Thing what would come to my Mind would be Settings>Privacy>Display but thins is more for Stand-By and turn off a Display.
Does Your Monitor have any own built-in Settings Menu were You can set it up? Maybe You should take a look there.