PINN doesn't boot with headless Raspberry Pi 5

[tanyanghan]

Describe the bug
Referring to this past issue: #825

The description is exactly the same as the stated in the issue above, except when I try to add the video configuration to cmdline.txt at the end of the exiting line, but it still doesn't boot up.

video=HDMI-A-1:1920x1080M@60D

To reproduce
This is a clean install on a Raspberry Pi 5 8GB in Argon NEO 5 with 512GB m.2 NVME SSD (PCIE Expansion).

Actual behaviour
The Pi activity light blinks for a couple seconds, then pauses and blink once, and then nothing happens. If I plug in the monitor at this point, nothing happens.

It works if I have the HDMI plugged in with a monitor switched before powering up the Pi.

Expected behaviour
It should boot up without HDMI connection.

System

Raspberry Pi OS Lite:
Linux raspberry-pi5 6.12.62+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.62-1+rpt1 (2025-12-18) aarch64 GNU/Linux

PINN - P3.9.7

[ncasquinha]

@tanyanghan
video=HDMI-A-1:1920x1080M@60D has to be added at the end of the 1st line in cmdline.txt , simply give it a space and paste it.
it only processes the 1st line

NOTE: the cmdline.txt file is from PINN's partition, not from Raspios or any of your possible OS's, it's the one from PINN that most likely is locking your boot, at least that was it for me after a long way troubleshoouting it.

[procount]

PINN p3.9.7 is deprecated. PIN p3.9.8 is now available.

[ncasquinha]

I think that's the one I have installed, but I'm not sure to be honest.
Anyway, my reply was to try and help regarding the issue of not booting while running headless, was also driving me nuts and lost a few hours trying to fix it. Thank you