Regression and UI Freeze (5.15 -> 6.2) in QTableView with Accessibility

We have a problem with our application displaying 10000+ rows with 50 columns in a QTableView on Windows

Since we updated the project from Qt 5.15 to Qt 6.1 and Qt 6.2, as soon as the user first clicks on a row, there is a huge delay (more than 3 minutes) before the row get selected
After this first click, everything is correct and the other row selections are fast

It seems to be related with an accessibility problem, and by using a debugger I have found that there seems to be related with a new code for Qt 6 in the function QWindowsUiaMainProvider::notifyFocusChange
in
qtbase/src/plugins/platforms/windows/uiautomation/qwindowsuiamainprovider.cpp

the suspect part is

if (accessible->tableInterface()) {
int count = accessible->childCount();
for (int i = 0; i < count; ++i) {
QAccessibleInterface *item = accessible->child;
if (item && item->isValid() && item->state().focused)

}
}

the way this code search for focused items seems to be problematic, as there can be 500000+ elements to check

Any way to make this thing faster ?
Is there a way to completely disable Accessibility for QTableView ?

I will be happy to help if I can

thanks for your answer

Philippe