Ubuntu 20.04 missing hdmi sound device after monitor goes to sleep mode

Have a following config:

• Ubuntu 20.04
• Philips 278e connected via hdmi cable into GTX1060

I use monitor's dynamics for sound output. Device shown in a list called HDMI / DisplayPort 2 (GP106 High Definition Audio Controller)

After monitor goes to sleep mode (that is set for 5 minutes) and restores from sleep, HDMI audio device disappears from output devices list.

After restarting pulseaudio (by pulseaudio -k or systemctl --user restart pulseaudio.service) device appears in the list again and is available for playing sound.

It makes me restart pulseaudio each time I leave my PC for more than 5 minutes, but restarting it causes one more problem: some applications that use sound devices (Slack, Spotify) loose them and require restarting after restarting pulseaudio as well.

I found several topics regarding the same problem (for discrete or onboard video), but none of them suggests anything more that restarting pulseaudio in order to fix sound.

But restarting first pulse, and then every application that affected several times a day doesn't look like a perfect solution.

Answering to myself: the only thing that helped - updating kernel from 5.4 to 5.9. With 5.9 no other fix needed.