I think there is a bug. I re-ran my standard model, expecting it include an additional period due to the 2020 data, but it did not. It used the same number of periods as before the 2020 update.
So I went into the single-year spreadsheet, set it to 30 years starting in 1991 and it quits in 2018! No 2019 or 2020 data seems to be used. To confirm, I set the spreadsheet run to 1992 - it still quits at 2018.
Looking back to last year, it did appear to increment correctly when the 2019 update was added.