If installed through the respective app store...|
QNAP and Synology NAS both keep a backup of the latest P5 configuration database in a separate backup folder. Uninstalling P5 will not delete those backup copies. When reinstalling P5, the P5 installer will restore the backed uo P5 configuration database from that backup folder.
If you wish to start over with a new, fresh, clean P5 install on either device, you will need to delete the content of the backup folder prior to reinstalling P5. The paths to the respective P5 backup folders are: