I built a custom Boot2Qt image (5.11.2) for the Raspberry Pi 3B following the guide at url
I wrote a simple QML application with a WebEngineView but crash at startup:
Sandboxing disabled by user.
Received signal 11 SEGV_ACCERR 000076ec2000
#0 0x00007268f4da <unknown>
#1 0x00007338d346 <unknown>
[end of stack trace]
Calling _exit(1). Core file will not be generated.
Using the standard image for the Raspberry (QtCreator - Tools - Flash Boot to Qt to device) everything works properly.
I tried also the WebBrowser demo application in Qt Launcher with same results.