Exception (read access violation) thrown at program termination for debug build

I just upgraded from qt5.14 to 5.15 and this exception now happens in my own software using qt3d, as soon as i terminate the program, but only for debug build, not release.

It also happens to most, but not all qt3d examples (does not happen with 3d-text example). It happens e.g. with advancedcustommaterial example (in ...Qt-5.15.0\examples\qt3d\advancedcustommaterial).

Perhaps I have filed this bug under the wrong qt 5.15 version.
I did a "git checkout 5.15" yesterday (17.06.2020), and "git branch" command returns "5.15 dev"

Both examples and qt5 was compiled with MS Visual C++ Compiler 16.6.30204.135 (amd64)

See screenshot with stack trace and more details