Hello Marc, When you manually adjust the clock does the clock hour and minute change? It sounds as if you may have done these steps already however, we do need to exhaust all troubleshooting. Enter display menu by pressing the gear button all the way on the left then arrow down to Factory Reset in the Menu settings. Change the next option to "YES" then the display will tell you to press the "Check mark" twice. Please let us know if this issue continues. If the issue does continue, when and where was this purchased? Thank you.