Click Enter in the CommonButtonBase game does not trigger Navigation Accept, but other Accept keys can trigger.
I thought something else was blocking Enter,But by removing Enter from KeyActionRules, UMG can get Enter in OnKeyDown normally.
// By default, enter, space, and gamepad accept are all counted as accept
KeyActionRules.Emplace(EKeys::Enter, EUINavigationAction::Accept);
KeyActionRules.Emplace(EKeys::SpaceBar, EUINavigationAction::Accept);
KeyActionRules.Emplace(EKeys::Virtual_Accept, EUINavigationAction::Accept);