QList::insert'ing indices out of order warns index is out of range

This code makes Qt log a warning:

QList<int> test;
test.insert(1, 0);
test.insert(0, 0);

The warning is:

QList::insert(): Index out of range

Using QList::reserve does not make a difference, even if the reserved size is orders of magnitude more than necessary. This still results in the warning:

QList<int> test;
test.reserve(2);
test.insert(1, 0);
test.insert(0, 0);

This does not warn:

QList<int> test;
test.insert(0, 0);
test.insert(1, 0);

This is a regression from Qt 5.14. I presume it is somehow related to the upcoming changes to memory management in QList in Qt6, but if so I would have expected using QList::reserve to resolve the warning.