QWebEngineView setUrl()/load() methods in some case divide page in two parts

When the page executes a setUrl () or load () of a host, when loading the page it is divided into 2 parts, when has finished, the loaded page it is seen in full screen correctly. In some cases the page is loaded and remains permanently halved as in the attached image. To replicate the problem, you can try a host that is not responding. When the timeout has elapsed, the page goes to the non-reachability page, but sometimes it remains permanently halved. With Qt 5.10.1 i haven't this problem.