Hi, I tracked down the issue with the original firmware, don't know if it's the same (where can I submit pull request for the original fw?), it's looking for a lowercase MAC in an array with uppercase indexes.
This fixes it on the original FW: client_function.js, line 2407:
FROM
clientListCode...
Hi, I'm having troubles too. AC68U here. Tried both ASUS and Merlin modes, various combinations of firewall and QOS, but I only managed to see the HTTPS green lock a couple of times without the page being loaded (now not even that anymore)