@JadenJSJ @fustom I finally resolved this on my machine. It turns out that containerd service was causing the issue. It's not specific to pihole but any docker container and running lsof. I found out that when I do a systemctl status, containerd was running under system
It needs to run under docker.service. I did the following steps:
sudo systemctl stop containerdsudo systemctl disable containerdsudo reboot
After that when I do a systemctl status I see that containerd now runs under docker:
And now pi-hole docker runs without any issues. I hope this helps you out too.