Cannot connect to wifi

I would try this procedure:

Settings>General>Reset>Reset Network Settings.. keeping in mind that this process also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before, but NO other data is affected.

When done, restart your device and test it.

If the issue still persists, since your iPhone is still on warranty, have it inspected at an Apple Store or AASP:--> Apple – Location Selector

Regards

Giulio

Have you tried to connect your device to a different Wifi Network?

What happens when you try?

Regards

Giulio

Glad it helped :-)