I've tried this before too, with no luck, but here it is again:
In the resolv.conf, the only thing that I've noticed is the options:
nameserver 127.0.0.53
options edns0
Updated the nameserver to 1.1.1.1 and ran the verbose version and it always fails here: [i] Downloading and Installing FTL...
It just haults and stops working at the step above.
Full info:
[i] Installer Dependency checks...
[✓] Checking for apt-utils
[i] Checking for dialog (will be installed)
[✓] Checking for debconf
[i] Checking for dhcpcd5 (will be installed)
[✓] Checking for git
[✓] Checking for iproute2
[✓] Checking for whiptail
[i] Using Google (ECS)
[i] Your static IPv4 address: 192.168.4.4/24
[i] Your static IPv4 gateway: 192.168.4.1
[✓] Set IP address to 192.168.4.4
You may need to restart after the install is complete
[i] Unable to find IPv6 ULA/GUA address, IPv6 adblocking will not be enabled
[i] IPv4 address: 192.168.4.4/24
[i] IPv6 address:
[i] Web Interface On
[i] Web Server On
[i] Logging On.
[✗] Check for existing repository in /etc/.pihole
[✓] Clone https://github.com/pi-hole/pi-hole.git into /etc/.pihole
[i] Main Dependency checks...
[✓] Checking for cron
[✓] Checking for curl
[✓] Checking for dnsutils
[✓] Checking for iputils-ping
[✓] Checking for lsof
[i] Checking for netcat (will be installed)
[✓] Checking for psmisc
[✓] Checking for sudo
[i] Checking for unzip (will be installed)
[✓] Checking for wget
[i] Checking for idn2 (will be installed)
[i] Checking for sqlite3 (will be installed)
[✓] Checking for libcap2-bin
[✓] Checking for dns-root-data
[i] Checking for resolvconf (will be installed)
[✓] Checking for libcap2
[i] Checking for lighttpd (will be installed)
[i] Checking for php-common (will be installed)
[i] Checking for php-cgi (will be installed)
[i] Checking for php-sqlite3 (will be installed)
[✓] Enabling lighttpd service to start on reboot...
[✓] Creating user 'pihole'
[i] FTL Checks...
[✓] Detected x86_64 architecture
[i] Checking for existing FTL binary...
[i] Downloading and Installing FTL...
I spoke too soon, I did a restore prior to the pihole failed install and tried the commands and then the "cur -sSL..." and it halted the system when I ran the command.