After the commit 0f6135ae6d97f77c1a737a26f67bf3242940e11c in qtbase,

code that relied to set the popupmode of a QToolButton prior to the QMenu creation (for lazy loading) and menu set are now ignored and always set to MenuButtonPopup

This breaks toolbuttons of applications that are supposed to have toolbar buttons that are purely a menu without a main action to be triggered which wish to create the popup menu only on trigger as it might be an expensive action.

Attached example creates a split button with te down arrow on click, while it should just open the menu and nothing else.

In KDE, this breaks all applications using KHamburgerMenu, in the attached screenshot, the hamburger menu shouldn't have a down arrow