Thats a valid ULA:
Doesnt that one work instead of GUA's and/or LLA's?
You can test on a client with nslookup eg:
nslookup pi.hole fd11:xxxx
Sometimes you have to add the local interface eg for %eth0:
$ nslookup pi.hole fe80::xxx%eth0
Server: fe80::xxx%eth0
Address: fe80::xxx%2#53
Name: pi.hole
Address: 10.0.0.4
Name: pi.hole
Address: fe80::xxx
EDIT: Oh sorry, I dont have IPv6 enabled on my LAN so thats why I address the LLA in my example 
Most all hosts can auto construct an LLA without any RA prefix etc.