Describe the bug
The Raspberry Pi 4 will not boot if GPIO 1 / ID_SC is pulled low. Admittedly, this shouldn't happen, but it semingly is on my 8G Pi 4 when left floating: to get it to reliably boot I need a wire between a 3v3 pin and pin 28. The Pi 2 is unaffected.

To reproduce
Connect a ground pin to pin 28 and reboot. Watch in wonder as your Pi boots as far as the rainbow screen and freezes. If you're network booting, you can see the thing stopping before the DTB is loaded.

Expected behaviour
The Pi boots.

Actual behaviour
The Pi doesn't boot.

System

• Which model of Raspberry Pi? e.g. Pi3B+, PiZeroW

Pi 4 2G (tied to ground), Pi 4 8G (left floating or tied to ground, on apparently my board only; possibly also user jk123 on the forums, too).

• Which OS and version (cat /etc/rpi-issue)?

Doesn't get that far.

• Which firmware version (vcgencmd version)?

Everything that I have tried from when I got it (last Tuesday) until today: da3752a358a86014cdcce5fc3be5b18d7ec074c4 and 31eda665dcc45e61650a2ef018ef2cf94091c46f at least.

• Which kernel version (uname -a)?
  Irrelevant.

Logs
Please see this post for details.

Additional context
As I say, this seems to affect my new 8G Pi 4 when left floating, which has caused me much headscratching over the last week. Obviously, the ID I2C pins should be left clear when unused, so this is a little concerning. force_eeprom_read=0 has no effect.

I can't see any obviously-knocked-off pullup resistor, but it's quite a complicated board these days and I don't know where I should be looking, should such a thing exist.

config.txt:

arm_64bit=1
gpu_mem=256
uart_2ndstage=1
kernel_address=0x80000

# start_file=start4db.elf
# fixup_file=fixup4db.dat

force_eeprom_read=0

dtoverlay=miniuart-bt

# over_voltage=1

initramfs initrd.gz
hdmi_enable_4k=1

# dtoverlay=w1-gpio,gpiopin=11
hdmi_ignore_cec_init=1

# Enable audio (loads snd_bcm2835)
dtparam=audio=on
bootloader_update=1

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
dtoverlay=vc4-fkms-v3d
# dtoverlay=vc4-kms-v3d
max_framebuffers=2
enable_uart=1
# dtoverlay=uart5
# dtoverlay=uart0
start_x=1
dtparam=act_led_trigger=heartbeat
disable_overscan=1

[all]
#dtoverlay=vc4-fkms-v3d
hdmi_enable_4kp60=1