[5.12.4] Assert at QWidget::mapTo()

I just updated my program to the latest Qt5.12.4 from 5.7, but I have a assertion triggered from QWidgetsd.dll.

My program is a dialog within a QScrollArea will fill with different contents at begining showing.

In debug mode, an assertion is occured when I showed my dialog 2 or more times then drag the area's scrollbar or scrolled my wheel. Many assertion popup dialog shown as the attaching picture shown.

In release program crashed immediately.

I tried both vs2019 and vs2017, they all have the same problem, but downgraded to 5.12.2 neither of them. 5.12.3 was not tested, i'm not sure this problem whether occuring on it.

I'm attaching two screenshots, one is the popup assert dlg, one is the stack call back in vs.