There is no problem on connecting to raspberry pi 4 with connecting HDMI cable into raspberry pi 4. But I can't connect without connecting HDMI cable.
The below is os information which I installed raspberry pi 4 .
pi@raspberrypi:~ $ cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 10 (buster)"
NAME="Debian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"
VERSION_CODENAME=buster
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
pi@raspberrypi:~ $ unanme
bash: unanme: command not found
pi@raspberrypi:~ $ uname -a
Linux raspberrypi 5.10.103-v8+ #1529 SMP PREEMPT Tue Mar 8 12:26:46 GMT 2022 aarch64 GNU/Linux
pi@raspberrypi:~ $ uname -mrs
Linux 5.10.103-v8+ aarch64
