Unable to boot/login Raspberry Pi 4 Bookworm headless

Start by reproducing the headless boot failure on a Raspberry Pi 4 running Pi OS Bookworm, using the listed kernel version and the documented power-cycle steps. Compare the behavior of /boot/config.txt with force_hdmi_hotplug=1 and /boot/cmdline.txt with the video=HDMI-A-1 setting. Done means the Pi boots and provides SSH or web access without a connected monitor.

Describe the bug

This issue appeared only with Pi Bookworm OS.
With Bullseye, no changes were required.

A Raspberry Pi 4 running the latest full version of Pi OS Bookworm is unable to boot/ssh or access webservers headless (no monitor).

The Pi refuses to boot into the OS(for lack of a better term) without detecting a monitor.

When switching it on, the Red LED lights up and the Green LED blinks in a random fashion(ie.) Shows activity going on, after a few seconds, the Green LED goes dull and only the Red LED along with the Ethernet port light up. At this juncture, attaching a physical monitor does nothing, I am required to power cycle the Pi in order for the boot process to complete.

When a monitor is connected, the Pi boots and is accessible via SSH as expected, without any issue.

This issue can be circumvented by adding "force_hdmi_hotplug=1" in /boot/config.txt

However, I had asked on the Raspberry Pi forums and was told the updated method (to let the kernel know) is to add "video=HDMI-A-1:1920×1080@60D" in /boot/cmdline.txt.

The second line of code (the "video=HDMI") when used alone, has no effect on my Pi. I am still forced to use a physical monitor to access the Pi.

I was told it might be an issue with my Pi and was asked to raise an issue here.

Adding relevant links to forum posts below:

Initial post asking for help -

https://forums.raspberrypi.com/viewtopic.php?t=357538&sid=b2ead654cea66533b423aace70947f1a&start=608

User Dom's reply about cmdline.txt -

https://forums.raspberrypi.com/viewtopic.php?t=357538&sid=b2ead654cea66533b423aace70947f1a&start=617

My response about cmdline.txt not working -

https://forums.raspberrypi.com/viewtopic.php?t=357538&sid=b2ead654cea66533b423aace70947f1a&start=620

Further conversation-

https://forums.raspberrypi.com/viewtopic.php?t=357538&sid=b2ead654cea66533b423aace70947f1a&start=621

Detailed explanation about my issue -

https://forums.raspberrypi.com/viewtopic.php?t=357538&sid=b2ead654cea66533b423aace70947f1a&start=622

Dom asking me to raise an issue here -

https://forums.raspberrypi.com/viewtopic.php?t=357538&sid=b2ead654cea66533b423aace70947f1a&start=636

Steps to reproduce the behaviour

Install Pi OS Bookworm GUI on Pi 4 8GB

Update to latest version including kernel.

Power off Pi.

Disconnect monitor.

Start the Pi.

Issue produced.

Connect monitor. Nothing will happen.

Power cycle (switch off and on) the Pi with the monitor connected, everything will work as normal.

Device (s)

Raspberry Pi 4 Mod. B

System

Pi OS Bookworm.

cat /etc/rpi-issue - Raspberry Pi reference 2023-10-10
962bf483c8f326405794827cce8c0313fd5880a8, stage4

vcgencmd version - September 21 2023 18:42:00
version 3094eda5aadf2c719edd2c68d1900884abc3dbca (clean) (release) (start)

unname -a --- Linux pi-home 6.1.57-v8+ #1688 SMP PREEMPT Thu Oct 12 15:14:26 BST 2023 aarch64 GNU/Linux

Logs

No response

Additional context

Not found in Pi OS Bullseye.