Thats because these pages usually load through the Android System WebView app, which doesnt support autofill. But Google is ...
Android may soon open Captive Portals in an Android Custom Tab instead of a WebView, making it easier to access some public Wi-Fi networks.
To uninstall updates to Android System WebView, follow these steps: Open Settings, go to Apps -> Android System WebView. Now, tap on the three-dot menu on the top right. Next, tap on the ...