Brightness set to maximum instead of zero when laptop screen awakes from sleep mode

I have been experiencing a similar situation to the one described in the link below. Unfortunately, the user who created that thread did not follow up after clarifying the problem so there is no proper solution offered. Pity, because that is the closest I could find.

https://forums.linuxmint.com/viewtopic.php?t=277385

The problem is related to the laptop screen going into sleep mode (just the screen, not the whole system). When the screen awakes from sleep mode screen brightness is automatically set to maximum, instead of the user defined value. I could not find a similar situation in the forum here, but maybe some of you have met and solved the same problem in the past. In my case, this only happens if brightness has been defined to zero before the screen goes into sleep mode.

Brightness settings work fine and are remembered properly in all other situations (booting, rebooting, sending the system to sleep or hibernation and back, screen coming back from sleep mode when a positive value is defined for brightness, etc.). This is happening with Trisquel 9, not tested with Trisquel 10 yet.

I am posting this here because the problem is not blocking, nor absolutely annoying. I noticed it only recently while setting the screen brightness to zero so I could keep participating in an audio conversation without throwing useless kWh to the walls. I can simply tell the screen not to go to sleep, or to go to sleep sooner with non zero brightness defined, but the bug remains.