[REG 5.13->5.14] Beginning of vertical text is not displayed after resize in QWebengineView

I want to display a vertical html with QWebEngineView. However, after decreasing the height with mouse (drag on the margin of window), the beginning of the content is not shown (I can not scroll more to the right), and after increasing the height with mouse there is large white space in the front (right side).

I tested on both Manjaro Linux and Windows. I can only reproduce this in Qt Webengine 5.14. In Qt Webengine 5.13 this does not happen, but text is not reflowed when height changes, so I am suspecting content size is not updated after reflow in 5.14.

In my sample code, the QWebengineView automatically resizes after two seconds, so you don't need to use mouse to resize manually.