Search doc functionality for online documentation is misbehaving

Goto https://qt-project.org/doc/qt-4.8/
Use input box with "Search doc" right of it.
Type any Qt class name e.g. "qmenu"
During typing a drop down list appears. In the list "QMenu" will appear. Only if this entry is selected and the user shows a bit of patience the online doc for QMenu of the selected version e.g. 4.8 will come up.
Pressing return after typing the correct name will have the same result as a google search.
Certainly this google search may show also the entry as to be found directly, but to make it worse in some trials it brought up the older 4.7 doc version in the list. And also the version selection on the right holds the older version.