lookup to 77.68.81.103

[Y9fK]

lookup to 77.68.81.103

[sjt5]

This (non-obvious) issue is because *.cache.lancache.net (inappropriately IMO) resolves on the global Internet.
On your DNS server a Domain Override needs to be created for:

cache.lancache.net

Pointing to your lancache-dns server IP.
(lancache server 192.0.2.2)
(non-lancache DNS server 192.0.2.1)

Improper configuration:

C:\Users\SomeUser>nslookup uplay.cache.lancache.net
Server:  yakko.somelan.lan
Address:  192.0.2.1

Non-authoritative answer:
Name:    uplay.cache.lancache.net
Address:  77.68.81.103

Proper configuration:

C:\Users\SomeUser>nslookup uplay.cache.lancache.net
Server:  yakko.somelan.lan
Address:  192.0.2.1

Non-authoritative answer:
Name:    uplay.cache.lancache.net
Address:  192.0.2.2

Would be awesome if whomever owns/runs the webserver for cache.lancache.net would add a custom HTTP header pointing to lancache documentation or something giving those troubleshooting a clue bat instead of simply 404'ing every HTTP/HTTPS request. ):

Hope this post helps others scratching their head with this issue.