That’s odd, but apparently not unheard of (All configurations lost).
Did you happen to check if the .sqlite database for the job was also missing?
I believe the dbconfig.json file includes the list of jobs Duplicati is aware of (even including deleted jobs) - if it was only that file that got reset and your .sqlite file is still around you might be able to attach the old .sqlite file to the new backup job rather than having to rebuild the database.
If the old .sqlite file is NOT still there, then what you’ve done (including having to wait for the downloads) is likely the only way to continue adding more versions to that backup set.
Sorry - I’m not sure about whether the OverallProgress message is indicating 0.78% or 78%.