Thats because these pages usually load through the Android System WebView app, which doesnt support autofill. But Google is working on a way to make logging in easier and way less of a hassle.

This is the easiest solution to fix Android apps crashing issue. To uninstall updates to Android System WebView, follow these steps: Open Settings, go to Apps -> Android System WebView.

The February Google Play System update has begun arriving on several devices now. The updates include improvements to core Android components like WebView, Google Play Services, the Play Store ...