Can someone please help me configure IPv6 on my phone, because it doesn't work, but should be.
I have static prefix /60 from my wireguard tunnel. IPv6 works on my wi-fi connected laptop, on my wire connected PC, but not on my phone.
On router main page I see 3 DHCP leases, and only two DHCPv6 leases:
What mobile config? It's not wireguard client. I've already told you the case is not about mobile configuration.
Or maybe your are talking about this configuration?
If it's an Android mobile then it's expected since it doesn't support DHCPv6. (Some vendors might have their own DHCPv6 implementation, I'm not sure.)
Android and ChromeOS require SLAAC.
Edit: I see that it's an Android mobile, and it has got IPv6 addresses. Don't know why it doesn't work.
(Though it uses incorrect ULA prefix, but it shouldn't matter. A ULA prefix should be generated using a random value.)
fd42:42:42::/64 is also a ULA prefix (though not created using the ULA algorithm which uses a random value). You should make sure all prefixes you assign to the LAN interface can be used since it's up to the clients to choose which prefix/address they use at a given time.