ASSERT in QAccessibleWidget when calling setMaxLength on QLineEdit

We are opening a new dialog with a QLineEdit and on init we do this:

lineEdit->setValidator(...);
lineEdit->setMaxLength(10);

When running this code our GUI stops with this assertion:

Program: C:\Qt\Qt5.12.5\bin\Qt5Cored.dll
Module: 5.12.5
File: accessible\qaccessiblewidget.cpp
Line: 228
 
ASSERT: "w" in file accessible\qaccessiblewidget.cpp, line 228
 
(Press Retry to debug the application) 

It stops in debugger on the stacktrace shown in Stacktrace.png

We reproduced this error with higher probability when the GUI is started in a Remote Desktop Connection.