Hi,
I updated my X86_64 router (thanks to the UEFI image !!) with 21.02.0-rc2 and I want to declare a bug (or a strange behaviour) about DHCPv6.
All is working fine if I choose a 12h (or more) lease time.
If I configure a shorter lease time (2m, 15m, 1h or even 11h) no DHCPv6 lease is granted (to any host), only SLAAC is working.
However, I thought that the lease time parameter only concerned DHCPv4 but it seems to also impact DHCPv6 server.
I had to put my old WD N750 back into service under OpenWRT 19.07.7 which does not have this problem of lease time (because 19.07.7 has no X86_64 UEFI capable image to deploy it on my X86_64 router)
Regards
Herve