It wouldn't.
pihole-FTL.db is Pi-hole's long-term query database.
Any IP that has issued a DNS request to Pi-hole in the past will show up there.
Before Pi-hole Core v5.3, IP addresses were stored in setupVars.conf.
But as explained, Pi-hole does not depend on being configured for a specific IP address for quite some time now. Consequently, storing and accessing of IPV4_ADDRESS (and IPV6_ADDRESS) in setupVars.conf has been removed from Pi-hole's installer with Pi-hole FTL v5.8, Web v5.5 and Core v5.3 released in April 2021.
As you are running a current version, that would confirm that your issue is with your network configuration, which your Pi-hole wouldn't touch (unless your OS would run dhcpcd for network management).
As explained in my first post:
You won't get that option, unless your OS would run dhcpcd (mostly pre 12/Bookworm Raspberry Pi OS distros):
Your description suggests that you've tried to set a static IP on the host itself.
How did you do that?
Please try to upload a debug token after temporarily resetting the nameserver:
sudo nano /etc/resolv.conf
Edit the nameserver line to nameserver 9.9.9.9 or your preferred third party DNS service, save and exit.
Run
pihole -d
and upload the debug log.
Also, please share the output of
sudo pihole-FTL dhcp-discover