Suddenly iphone disconnected from wifi. And now its not connecting again. All other devices are connected to the same wifi and working fine. I have restarted my router and iphone but its not connecting. I reset my iphone network settings but its not

Since you have already tried resetting network settings, please try...

Reset All Settings: All settings—including network settings, the keyboard dictionary, the Home screen layout, location settings, privacy settings, and Apple Pay cards—are removed or reset to their defaults. No data or media are deleted.

1. Reset All Settings: Return iPhone settings to their defaults - Apple Support:- Return iPhone settings to their defaults
2. You can return settings to their defaults without erasing your content.
3. If you want to save your settings, back up your iPhone before returning them to their defaults. For example, if you’re trying to solve a problem but returning settings to their defaults doesn’t help, you might want to restore your previous settings from a backup.