Plasma Mobile goes back to lockscreen when the phone isn't charging

[plaristote]

Greetings !

I have the KDE edition pinephone, and after an update, I've seen that when it wasn't plugged, it wouldn't stay unlocked more than a few seconds. Nothing special seems to be happening, just the session getting locked again. I kept making updates, but nothing's changed (well, lots changed, but not this specific issue).
I checked out what happened with journalctl, when unlocking the phone while unplugged:

Code:

-- Journal begins at Sun 2021-06-06 02:39:45 CEST. --
Jun 11 19:23:01 plasma-mobile mtp-probe[7231]: checking bus 1, device 15: "/sys/devices/platform/soc/1c1a000.usb/usb1/1-1/1-1.3"
Jun 11 19:23:01 plasma-mobile mtp-probe[7231]: bus: 1, device: 15 was not an MTP device
Jun 11 19:23:02 plasma-mobile upowerd[4309]: treating change event as add on /sys/devices/platform/soc/1c1a000.usb/usb1/1-1/1-1.3
Jun 11 19:23:02 plasma-mobile systemd-logind[3705]: Watching system buttons on /dev/input/event7 (SEM USB Keyboard Consumer Control)
Jun 11 19:23:02 plasma-mobile systemd-logind[3705]: Watching system buttons on /dev/input/event6 (SEM USB Keyboard)
Jun 11 19:23:02 plasma-mobile systemd-logind[3705]: Watching system buttons on /dev/input/event8 (SEM USB Keyboard System Control)
Jun 11 19:23:02 plasma-mobile mtp-probe[7261]: checking bus 1, device 15: "/sys/devices/platform/soc/1c1a000.usb/usb1/1-1/1-1.3"
Jun 11 19:23:02 plasma-mobile mtp-probe[7261]: bus: 1, device: 15 was not an MTP device
Jun 11 19:23:04 plasma-mobile xdg-desktop-portal-kde[4529]: xdp-kde-background: GetAppState called: no parameters
Jun 11 19:23:34 plasma-mobile xdg-desktop-portal-kde[4529]: xdp-kde-background: GetAppState called: no parameters
Jun 11 19:23:50 plasma-mobile dbus-daemon[3694]: [system] Activating service name='org.kde.powerdevil.backlighthelper' requested by ':1.39' (uid=1000 pid=4342 comm="/usr/lib/org_kde_powerdevil ") (using servicehelper)
Jun 11 19:23:51 plasma-mobile dbus-daemon[3694]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper'
Jun 11 19:23:54 plasma-mobile dbus-daemon[3694]: [system] Activating via systemd: service name='org.freedesktop.ModemManager1' unit='dbus-org.freedesktop.ModemManager1.service' requested by ':1.137' (uid=1000 pid=7269 comm="/usr/lib/kscreenlocker_greet --immediateLock --gra")
Jun 11 19:23:54 plasma-mobile dbus-daemon[3694]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.ModemManager1.service': Unit dbus-org.freedesktop.ModemManager1.service not found.
Jun 11 19:23:54 plasma-mobile dbus-daemon[3694]: [system] Activating via systemd: service name='org.freedesktop.ModemManager1' unit='dbus-org.freedesktop.ModemManager1.service' requested by ':1.137' (uid=1000 pid=7269 comm="/usr/lib/kscreenlocker_greet --immediateLock --gra")
Jun 11 19:23:54 plasma-mobile dbus-daemon[3694]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.ModemManager1.service': Unit dbus-org.freedesktop.ModemManager1.service not found.

Nothing really stands out to me... I see something related with kscreenlocker, but I don't know what happens there.

Would anyone know where I should look next ?