Unable to connect eduroam wifi

an you connect to other Wi-Fi networks? If you can, it is a problem in the router, not in your iPhone.

More generally:

• Apple’s guidance→If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network - Apple Support. If that doesn’t resolve the problem you will have to provide a lot more information, including, among other things:
• All networks, or one specific network?
• Is it a secured network, or open network?
• What is the message when you try to connect?
• Does the network have MAC filtering enabled (aka Access Control)?
• Do you control the network, or is it someone else’s network? If you control it, restart your router by removing all power for about 15 seconds.
• Do you have Private Address enabled for the network?
• What other troubleshooting have you done?
• Do you have VPN installed? Try uninstalling it and its profile.