I am getting crash reports on Google Play after I compiled my Android app with Qt 5.12 that did not occur with Qt 5.11. Sorry that I cannot provide much information or a reproducible example. The only information I have are the stack traces on Google Play, which show only the function that the crash occured in:

signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
in _ZNK16QQuickEventPoint11grabberItemEv+23

The bug seems to occur infrequently, but regularly. It never occured when the same app was still compiled with Qt 5.11. The bug might be related to QTBUG-65454. My app is QtQuick based, does dragging & dropping, and there are some event handlers that take some time if the CPU is already under load (so it could be timing-related).