Qt Qtwebengineprocessd not terminated when stopping debugging in VS 2017

When using Microsoft Visual Studio Community 2017 (v15.7.3) with Qt Visual Studio Tools (v2.2.1) and stopping debugging from within VS, all Qtwebengineprocessd processes remain running (as background processes) with an unexpected high cpu usage. If exiting the application regularly, the processes are terminated as expected.

The process is started as a subprocess of the parent application as intended. Each webview gets its own webengine process.

When stopping the debugging in VS

none of the webengine subprocesses are closed. Instead they are running as background processes with a considerable increase in cpu usage. 
The image below shows what happens if two webviews were opened in the application.

If only one webview was opened (or none and QtWebEngine was just included), the webengine process is shown as standalone.

The more often this procedure is repeated, the larger the stack of webengine processes becomes, with a massive effect on cpu usage.

Compiling with Qt v5.10.0, the webengine processes terminate as expected.