Laza - in case you're interested, here's the evidence of what the change has produced. Take a look at what's in the .info file for 2020, vs. what's in there for 2021. I've renamed the files, just to keep it obvious.
Thanks for investigating this! I asked David to not fall back to file date when using getCameraDates, as this ruins other user's albums. E.g. they place a single PDF file into an older folder and the date range is gone. Bille should have used file dates from the beginning, as his photos do not carry any camera dates. I wasn't aware the wrong dates will linger on after the change.