I was exploring the IPv6 settings even though my ISP might not support it and enabled it for some time then disabled it but it seems that many of my clients are still trying to use IPv6, maybe because of DHCP leases, I'm not sure what's going on. Some of my clients are trying to resolve IPv6 addresses and timing out.

Anyway, in the IPv6 LAN setting, I try switching to ND Proxy from SLAAC+Stateless DHCP and I click Save but return back to the page and it is still on SLAAC+Stateless DHCP. I may have to reset the router because I'm not sure what's going on, but the web ui seems broken given that the Save button isn't working.