You have created a new user profile service application and using old Profile DB.
So now when you search for user in manage user profile you get the result but you are unable to edit or check user's profile property.
Even if this happens with UPA connection.
Go to you internet explorer and click on tool or settings icon.
Click On Compatibility view settings.
Now add your URL /central admin name to it.
Click OK and your page will be refreshed.
Now you will be able to edit the User properties.
Hope it helps :)
Happy SharePointing :)