Delphi host + WPF visualplugin : screen refresh issue

When dragging a delphi MDI child over the WPF plugin, and back out of it the dragged screen gets refreshed/repainted incorrectly:

Tried it with a blank plugin.xaml too, same behaviour. Minimizing and restoring the window solves it, but visually it’s not nice to our customers. Is this a known issue, and how can it be resolved?

Delphi form has OnDragOver event. if you call Repaint here, will it solve your problem?

that event doesn’t trigger, the form which doesn’t repaint isn’t being dragged over, its the one being dragged. in the meantime we made a workaound ourselves.

what workaround you have made?