Your debug log shows a number of improperly formatted entries in your blocklist - /etc/pihole/adlists.list As a result, Pi-Hole cannot load these into gravity.
The blocklists file should contain only URLs that lead to text files that consist of HOSTS formatted entries. It appears you may have tried to add whitelist or blacklist entries in the blocklist file.
In addition to improper URLs in the blocklist, you also have a large number of IP's in the blocklist file and some in your blacklist file. IP's are of no use in any of your Pi-Hole lists (black, white or block lists). Pi-Hole should never get an IP as a query, because if the client already has the IP, it would not request the IP. Pi-Hole only deals with domain names, which are then either blocked or sent to the upstream server for resolution to an IP.
Hello! Thank you for the clarification on what the issue here is. Do you think you could spare the time to educate me on what you mean about URLs that lead to text files that consist of HOSTS formatted entries? Do you mean like a directory path? Or something else? I really appreciate your fast feedback.
This is an example. Open the URL in a browser and you will see a list of domains in text format. Pi-Hole reads the domains from all your blocklists and constructs a master blocklist (gravity).