https://bugs.freedesktop.org/show_bug.cgi?id=109239
--- Comment #7 from Harry Wentland harry.wentland@amd.com --- If you didn't say you tried swapping monitors and cables I'd say it was a cable issue.
Are those high refresh rate displays (120Hz+)? If so you might want to give what's suggested in this comment a try: https://bugs.freedesktop.org/show_bug.cgi?id=102646#c41 It would help us diagnose the issue.