qmlls: "Warnings occured while importing module" but doesn't show any

After building https://invent.kde.org/plasma/systemsettings and opening it in Kate with qmlls enabled it shows warnings on several imports, e.g. in app/qml/SubCategoryPage.qml

It says "Warnings occured while importing module "org.kde.systemsettings"", but doesn't actually show the warnings. Even if there is something wrong with my code I'm left to speculate what that is

Running qmllint via 'make all_qmllint' doesn't show this warning.