I can, and I fear you are not going to like this. 
The expected outcome for this would have been a consistent `0.0.0.0` (click for my details)
through local DNS, i.e. Pi-hole
~ $ nslookup flurry.com
Server: 192.168.0.254
Address: 192.168.0.254#53
Name: flurry.com
Address: 0.0.0.0
through public filtering DNS
~ $ nslookup flurry.com 80.241.218.68
Server: 80.241.218.68
Address: 80.241.218.68#53
Name: flurry.com
Address: 0.0.0.0
through public DNS
~ $ nslookup flurry.com 8.8.8.8
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Name: flurry.com
Address: 98.136.103.26
Name: flurry.com
Address: 74.6.136.153
Name: flurry.com
Address: 212.82.100.153
tl;dr: Your router is redirecting all public facing DNS traffic to a DNS server of its choice, and it is also wrongly redirecting local DNS traffic for WiFi connections. (click for long version)
I deliberately chose a public filtering DNS server (fdns1.dismail.de / 80.241.218.68) I know to block flurry.com, as it applies the same matching blocklist as Pi-hole (i.e. http://sysctl.org/cameleon/hosts).
So when an nslookup flurry.com 80.241.218.68 provides an actual IP for flurry.com, it indeed has not gone through 80.241.218.68.
(Theoretically, fdns1.dismail.de could provide region-specific blocking based on the requesters IP's geo-location, but I am not aware it does so, and this finding is in line with all of your observations.)
What we are seeing is the result of something (supposedly, your router) redirecting DNS traffic (port 53) to some public DNS server.
This indiscriminately applies to all DNS traffic destined for a public IP (as all lookups through 80.241.218.68 failed consistently), so your router is definitely redirecting your public facing DNS.
However, while local DNS traffic seems to be correctly exempted for LAN, we just confirmed that WiFi-connected local DNS traffic is redirected also (as proven by your laptop's lookup through Pi-hole).
If you are not running a separate WiFi device (e.g. an access point) that may come with its own, misconfigured DNS settings, then again your router is the cause.
I am afraid that if your router does not expose any configuration option to change this, your WiFi devices will always be forced to use the DNS server your router is using, at least with its current firmware.
EDIT: You may want to reverify if you can revert your router to another firmware, as linked above (click on up arrow 'go to the quoted post' below):
EDIT-2: For the sake of other users with similar experiences, I think it would be beneficial if you'd be able to provide your router's exact current firmware version, either in your initial description or in your topic's title. Thank you for considering 