Empty source file can make Recreate download all dblock files fruitlessly with huge delay #3747 was fixed in 2.0.4.18. Unfortunately dblock put retry corrupts dindex, using old dblock name for index – canary regression #3932 seems to have been added in 2.0.4.16, and the purge issue mentioned (also affects repair) in 2.0.4.29.
So if you got your files back, the Duplicati version to resume backup on is a question, given issues in canary.