This debug log looks normal. Was this log generated when you were not having problems with Pi-Hole?
If so, then please reboot and if the problem recurs, then generate a debug log. You may have to edit /etc/resolv.conf to change your nameserver to 1.1.1.1 to be able to upload the log, so do that first before you try to upload the log. Steps for that appear below
sudo nano /etc/resolv.conf
edit nameserver 127.0.0.1 to nameserver 9.9.9.9 or your preferred third party DNS service, then save and exit.