Version:            (using Devel)
Installed from:    Compiled sources
OS:                Linux

As of about 9-11 April a change was introduced which stopped panels appearing on my right screen, instead they are put onto the left screen (even over another panel).  Individual widgets can be put onto the right screen, it is only panels which are affected.

Here is the output when trying to put a panel on the right screen.  I deleted my original panel so I do not have the output when it is trying to place an existing panel.

plasma(25779)/libplasma Plasma::Theme::image: Theme says: bad image path  "widgets/overlay"
plasma(25779)/libplasma Plasma::Containment::positionPanel: positioning non- horizontal panel; forced? false
plasma(25779)/libplasma Plasma::Containment::positionPanel: moved to QPointF(11686, -62)
plasma(25779) PlasmaApp::createView: Containment name: "Panel" | type 1 | screen: -1 | geometry: QRectF(11686,-62 1680x56) | zValue: 150
plasma(25779)/libplasma Plasma::View::updateSceneRect: !!!!!!!!!!!!!!!!! setting the scene rect to QRectF(11686,-62 1680x56) associated screen is -1
plasma(25779) PanelView::updatePanelGeometry: New panel geometry is QRectF(11686,-62 1680x56)
plasma(25779) PanelView::updatePanelGeometry: PanelView(0xcb9ab0) thinks its panel is at  QRect(0,994 1680x56)
plasma(25779) PanelView::PanelView: Panel geometry is QRectF(11686,-62 1680x56)
plasma(25779) PanelView::updateStruts: screen l/r/b/t offsets are: 0 0 0 0
plasma(25779) PanelView::updateStruts: screen l/r/b/t offsets are: 0 0 0 0
plasma(25779) PanelView::updateStruts: screen l/r/b/t offsets are: 0 0 0 0
plasma(25779) RootWidget::screenOwnerChanged: was, is, containment: -1 1 Panel(0xb059f0)
plasma(25779)/libplasma Plasma::Containment::positionPanel: positioning non- horizontal panel; forced? false
plasma(25779)/libplasma Plasma::Containment::positionPanel: moved to QPointF(11686, -62)
plasma(25779)/libplasma Plasma::Containment::positionPanel: positioning  horizontal panel; forced? true
plasma(25779)/libplasma Plasma::Containment::positionPanel: moved to QPointF(0, -278)
plasma(25779)/libplasma Plasma::View::updateSceneRect: !!!!!!!!!!!!!!!!! setting the scene rect to QRectF(0,-278 1680x56) associated screen is 1
plasma(25779) PanelView::updatePanelGeometry: New panel geometry is QRectF(0,-278 1680x56)
plasma(25779) PanelView::updatePanelGeometry: PanelView(0xcb9ab0) thinks its panel is at  QRect(0,0 1680x56)
plasma(25779) PanelView::updateStruts: screen l/r/b/t offsets are: -1680 -1680 0 0