DHCPv6 only giving out ULA, not delegated prefix

My home network gets the IP range 2601:XXXX:XXXX:XXXX::/64 from my ISP's prefix delegation, and FDYY:YYYY:YYYY::/64 as a ULA. As I expect, SLAAC gives IP addresses from both of these ranges to each device. I'm also using DHCP to give out addresses with nicer host parts. I added host part 101 for one of my hosts, and as expected, DHCP gives it FDYY:YYYY:YYYY::101. However, it doesn't get 2601:XXXX:XXXX:XXXX::101, which I'd like it to have. Is there a way to make odhcpd give out addresses for both the ULA and the delegated prefix?