Screen saver does not turn off monitor

[Gordon Fresh]

I am using Ubuntu Desktop 22.04 LTS Jammy Jellyfish on Raspberry Pi 4, and noticed a strange behaviour of the screen saver.

In settings -> energy -> power saving options I selected Screen Blank after 5 minutes. After 5 minutes of inactivity, the screen goes blank, the monitor says No Signal and turns off, but a few seconds after it turns on again, showing a completely black screen.

The desired behaviour here is that Ubuntu sends no signal to the monitor, so the monitor goes into low-consumption mode. But this is not happening, the monitor is on and showing a black screen.

I wonder how to solve this problem, especially given the current energy situation in Europe.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: gnome (not installed)
ProcVersionSignature: Ubuntu 5.15.0-1018.20-raspi 5.15.64
Uname: Linux 5.15.0-1018-raspi aarch64
ApportVersion: 2.20.11-0ubuntu82.2
Architecture: arm64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Sun Nov 27 21:35:58 2022
ImageMediaBuild: 20220809
SourcePackage: meta-gnome3
UpgradeStatus: No upgrade log present (probably fresh install)