Greetings @2neuron and @Gabor, I hope you both are doing great.
We tried reproducing the behavior that you are describing and here is what we found:
Duplicating a dashboard correctly sets the target device as the data source of the new dashboard, however, the device label associated to the variables isn’t changing as expected. This behavior might make it seem as if it was not working correctly, but it does.
Here is the proof:
In the following GIF, on the left part of the screen, you’ll be able to see a static dashboard with two widgets corresponding to temperature and Humidity variables on a device labeled lm335-yard.

Then, that dashboard is duplicated and the target device is now one labeled lm335-first-floor.
Checking the variables’ values directly from the device (right side of the GIF) demonstrates that the new dashboard is actually displaying the values corresponding to lm335-first-floor and not lm335-yard. In short, duplicating the dashboard is working correctly as intended, however, as can be seen from the GIF, the device label corresponding to those variables, is not changing, but this is only a visual bug, the functionality is not compromised.
I don’t rule out that I might be missing something in my thought and testing process, in which case I would appreciate your guidance to actually reproduce the error that you have brought to our attention.
With the above in mind:
- Thanks for your feedback, because that helped us to identify a possible source of error for our users.
- Let us excuse ourselves for the inconvenience, we will report to to our Dev team to have it fixed.
Taking the opportunity, I think this a the perfect instance to advise you about using Dynamic dashboards, a feature that allows you to have one single dashboard for multiple devices sharing the same structure variable-wise, and selecting the device from which data should be populate through a device drop-down selector.
Best regards.