[ul][li]Does the same thing happen if you launch Opus in other ways? e.g. Put an Opus icon on the desktop and try double-clicking it, then fully exit Opus, move the icon to another monitor and try double-clicking it there.
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[li]If you set Preferences / Launching Opus / From the Desktop to Disable and then double-click the desktop, does anything happen? It's possible you have two programs both reacting to desktop double-clicks.[/li][/ul]