It looks like I've found some resolution at this time, but far from a ideal resolution.
@jfb As you alluded to, my client (Mac laptop) was picking up IPv6 from the Google Router. There is no way to disable DHCP completely on the Google Router and/or disable IPv6, instead the only option presented is to restrict DHCP to an IPv4 address range. While I did reserve the IPv4 address for my Pi-Hole (192.168.1.100) with the Google Router and restrict my DHCP IPv4 range to the same address (DHCP Start Address = 192.168.1.100; DHCP Stop Address = 192.168.1.100), it seems the router was still leaking IPv6 and my client was picking up the IPv6 address, thus failing to block ads. My temporary workaround has been to disable IPv6 on my client. As such the ads are now being blocked now and http://pi.hole/ resolves successfully. This is not ideal as the very idea behind the Pi-Hole is to apply settings at the network level vs. making individual configurations on each client. Given this is a limitation with the Google-provided router, it seems my only option is to replace it with a more configurable router so I can disable DHCP completely. This post was helpful as well: Google fiber leaking ipv6 DNS - #3 by Chris_Anthony
I ran nslookup pi.hole and received the following output.. I assume this is correct?
Server: 127.0.0.1
Address: 127.0.0.1#53
Name: pi.hole
Address: 127.0.0.1
Name: pi.hole
Address: ::1
@MichaIng Your post was very helpful, I'm not sure why I didn't think to use htop. I had two directories still intact after following the cloudflared removal instructions I listed above:
/home/pi/cloudflared
/home/pi/argo-tunnel/cloudflared
After removing both directories, the processes are no longer running and I seem to have completely removed cloudflared.