The captive portal appears slowly on the wireless client when connecting to a Nebula AP

Zyxel_JoyLee

The Captive Portal is a web-based authentication that appears before users can access the internet. It intercepts all web traffic until the user has successfully pass captive portal.

The captive port page is stored on AP since the AP is managed by Nebula. 

When the user opens a browser or launches a web app, the AP intercepts the first HTTP or HTTPS request and then redirects the user to the configured captive portal login page.

The slowness may be related to a DNS resolution issue. Consider changing the DNS server to a public one, such as 8.8.8.8 or 1.1.1.1, to check if the issue improves."