PureOS Byzantium no longer warns when battery low

I sometimes forget to plug in the power supply. I remember once upon a time that it would show a clear popup before the power ran out completely so I could still quickly plug it in. However, now it doesn’t seem to give any visual warning anymore and just shuts down poof.

The battery % indicator at the top right is working perfectly. The battery itself also works fine. I don’t think this is a hardware issue.

I use GNOME Wayland on PureOS Byzantium on a Librem 15 v4 laptop.

Does anyone know if this is a setting, or a missing program or such?

This isn’t answering your popup question but first you can:
sudo apt install gnome-power-manager
and open it (leave it open so you can take a look at statistics from time to time) with (search for it works as well):

upower --monitor
Ctrl+c to quit:
upower -i /org/freedesktop/UPower/devices/battery_BATX

sudo apt install acpi

Otherwise below commands should run without any problems (for test purpose):
gsettings set org.gnome.desktop.interface show-battery-percentage false
gsettings set org.gnome.desktop.interface show-battery-percentage true

Install gnome-tweaks (if helps) or install and use the TLP CLI, if part of PureOS repo.