I have also experienced problems with Recreate Database. I was using Duplicati to backup to a USB connected WD 4 Tb drive. After several hours the computer locked up forcing me to do a hard reboot. When I restarted the backup, Duplicati warned me about problems so I did a delete and repair database.
Duplicati ran for 10 days recreating the database and did not look close to finishing so I aborted it. The backup source is 357 Gb. I can do a total backup from start in less than 3 days.
Recreating the database should not take longer than a full backup.
I am running 2.0.4.5_beta_2018-11-28 on Windows 7. I am backing up to a WD drive connected through USB3.