QWebEngineView Crashes on context menu

With browser sample, I can right-click repeatedly on the default qt.io page and reproduce the crash eventually. If I navigate to www.google.com and right-click on the white area, it crashes every time. Yahoo too, right click an image. I tried to override onContextMenuEvent to no avail as the crash happens before the event. The crash is within QtWebEngineProcessd.exe. Version 5.7.1 works fine.

EDIT: I have discovered that this only occurs within the debug build. It seems to work fine in release mode.

Problem Event Name: APPCRASH
Application Name: QtWebEngineProcessd.exe
Application Version: 0.0.0.0
Application Timestamp: 58814975
Fault Module Name: Qt5WebEngineCored.dll
Fault Module Version: 5.8.0.0
Fault Module Timestamp: 58814933
Exception Code: 80000003
Exception Offset: 008adf41
OS Version: 6.1.7601.2.1.0.256.48
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789