This is not normal. One thing appears in your debug log that may be a contributor:
*** [ DIAGNOSING ]: Networking
[✓] IPv4 address(es) bound to the eth0 interface:
10.160.0.2/32 does not match the IP found in /etc/pihole/setupVars.conf (https://discourse.pi-hole.net/t/use-ipv6-ula-addresses-for-pi-hole/2127)
Pi-Hole is setup to listen on this IP: IPV4_ADDRESS=xx.xxx.2.73. When I run a dig to this IP, I receive a valid IP in return.
I deleted the first two strings in the IP address because you are running an open resolver, which is very bad practice. You should close this open resolver.
The number of IPv4 addresses is countable. It may be less than you think and already too few for all Internet capable devices worldwide. Because there are fewer than 4.3 addresses available, depletion has been anticipated since the late 1980s, when the Internet started to experience dramatic growth. There are services out there that scan the entire Internet in a day (or even less), quickly discovering any new machines.
Please note: Security by obfuscation is not only a bad idea, but has been proven repeatedly to not work at all with IPv4 addresses.