after effect preview not work

When I leave AE open and take a break, a lunch (or leave it open overnight ), when I come back and hit the spacebar, it will play it once without sound and when I stop it and try to play it again, it does nothing. I can scroll the timeline and it composition updates, but can't play it back anymore. When I purge all the cache and memory it cleans it up and it also caches/renders it internally (green bar fills up) but it won't play it. When I check "cache before playback" on Preview panel then it time cursor will follow the caching process, but no way to really play it back in realtime with sound.

Restart always repairs it. My fellow animator next to me has the same issue.

Not really the dealbreaker type of thing, but kind of interrupts the flow every time it happens.

But, I figured it out

It seems to be an issue with audio hardware (and monitors connected with audio-supported cables). When I (1) removed external devices from windows audio settings and (2) changed audio hardware (File > Preferences > Audio Hardware) back to Speakers it started to playback my preview (AE needs restart to get the audio back though). (3) If you have headphones connected to the monitor audio output, then

This kind of explains the issue (and my situation after leaving AE open):

"When an audio-supported video cable is being used such as a DisplayPort or HDMI cable, Windows may change the default audio device to the audio-supported cable thinking another audio device is being used. The issue may be seen to occur when a portable is coming out of sleep as the system is detecting the audio-capable cable first."