Pinephone shuts itself down

[d-.-b]

Hi,

This problem occurs only when phone is unplugged.

I've set up the phone "Automatic Suspend" to 15 minutes when on battery and turned off the switch when Plugged In (so never Automatic Suspend when the phone is plugged).
"Screen Blank, Turns the screen off after a period of inactivity" is set at "never".

Problem is, when the phone is on battery, shortly after the 15 minutes to "Automatic Suspend", the phone seems to turns itself off. Power off.
I try to connect to SSH during that state, no connections, no ping, phone doesn't respond.

I tried to press the side button and wait around 6 seconds to press it again, still nothing.

The only way to get the phone back to work is hold the side button long enough for the small green led to lit then, the phone reboots.

I had this problem a while back (months back) but it did seems to have ended but now, for 1 week, that problem is back.

Im using Mobian with Bookworm on SSD and all the apt update apt upgrade frequently. 32gb phone model.

Thank you all in advance!