There is a Warning which we used to see, if we make any changes to the app web url. Basically, the below screen.
Like, if we change the domain name or move our APP Web to any other IIS, the above-mentioned warning will be coming. Basically, it is because of the difference between the URL which we gave on the below screen (appregnew.aspx) and the actual IIS URL.
The Redirect URL – We might have given something and the actual APP Web URL got changed. In that scenario, the above warning will be coming. Hence, to overcome this, go to the APP registry and update the Redirect URL.