[REG 5.15.0 b3->5.15.0] window embedded using QWinWidget not receiving any event (Qt MFC solution) in some integrations

This is a very specific bug, but very blocking for me :

When embedding a Qt window as a plugin within a (non-Qt) host app, using QWinWidget ( https://github.com/qtproject/qt-solutions/tree/master/qtwinmigrate/src ), my Qt window displays once and then no longer refresh (unless during a resize), and no longer receive any input event (such as mouse or keyboard).
For a little more context, I'm developping a VST3 plugin using Qt for the host app Cubase.

The issue occurs in the Steinberg Cubase and Steinberg Nuendo integrations, but not in Presonus Studio One or Cockos Reaper integrations using the VST3 plugin.

I've narrowed down the problem to this commit:

QEventDispatcherWin32: fix posted events delivering

https://github.com/qt/qtbase/commit/e0d80167c18b5a71acf4dac59f3e6f37292fa397#diff-76b4b966aaac13e64f6c131c1411fab8 https://codereview.qt-project.org/c/qt/qtbase/+/294403

Right before this commit everything works as expected, and after it's applied the problem occurs.

Any way this commit could be reverted or fixed ?