random and flq allocator in v6 prefix delegation isn't random

I've repeated single test in which I assign 10 prefixes from a pool with flq/random enabled. And every single time I got the same leases. Prefixes are not assigned one by one as in iterative allocator, there are randomised in the pool, but order of addresses are each time exactly the same. In my case those would be:

duid: 00:03:00:01:f3:f5:f4:f3:f2:10; iaid: 8527; address: 2001:db7:3:2::22a8; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:11; iaid: 4909; address: 2001:db7:3:2::d5a8; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:12; iaid: 4322; address: 2001:db7:3:2::f7d8; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:13; iaid: 9166; address: 2001:db7:3:2::3880; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:14; iaid: 8992; address: 2001:db7:3:2::4ec8; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:15; iaid: 2535; address: 2001:db7:3:2::8be0; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:16; iaid: 2830; address: 2001:db7:3:2::3020; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:17; iaid: 4240; address: 2001:db7:3:2::fda8; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:18; iaid: 7673; address: 2001:db7:3:2::fe88; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:19; iaid: 9410; address: 2001:db7:3:2::f720; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:20; iaid: 9679; address: 2001:db7:3:2::b950; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:21; iaid: 3421; address: 2001:db7:3:2::fa68; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:22; iaid: 5331; address: 2001:db7:3:2::1c08; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:23; iaid: 7755; address: 2001:db7:3:2::cb98; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:24; iaid: 6564; address: 2001:db7:3:2::4bc0; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:25; iaid: 7124; address: 2001:db7:3:2::138; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:26; iaid: 8736; address: 2001:db7:3:2::1ca8; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:27; iaid: 9068; address: 2001:db7:3:2::a308; prefix: 125
duid: 00:03:00:01:f3:f5:f4:f3:f2:28; iaid: 3412; address: 2001:db7:3:2::dfd0; prefix: 125

Order of assigned prefixes is the same for multiple pd pools configured in different subnets as long as prefix length is the same.

Config file: kea-dhcp6.conf logs: kea.log leases: leases.csv