On iOS 11 using Unity 2017.1.1p2 a call to InAppBrowser.OpenURL(differntURL); opens up the first URL that was initially called.
Example Code:
Debug.Log(String.Format(“///////// Trying to load:D {0}”, myURL));
InAppBrowser.ClearCache();
InAppBrowser.OpenURL(myURL);
myURL represents a string passed into the call as a variable.
Sample URL’s:
https://www.tesla.com/sites/default/files/model_x_owners_manual_north_america_en.pdf
https://www.starbucks.com
As mentioned the initial call opens the correct URL and then subsequent calls open the initial URL.