When the user imports exported app data (from a previous installation) or replaces a display with slightly different identifiers (due to a hardware failure for example), display identifiers don't match - the app detects the "same" (from user's perspective) / replacement display as a different display than the one found in the imported settings.
It would be nice to give an option to transfer all configuration data from the previous display with the wrong identifiers (marked in the app as a disconnected display) to the new display.