I assume this is foreign residential rental real estate. Is my assumption correct?
Note that you can not just arbitrarily go changing the depreciation period, as doing so will completely skew your depreciation history. It also does not change on it's own (unless there's one heck of a glitch somewhere) You need to look at the printout of the IRS Form 4562 for both 2019 and 2020, that prints in landscape format, with the title at the top that reads "Depreciation and Amortization report". Look in the "life" column and confirm beyond any doubt, (for that specific asset) that it's the same (or not) on the 4562 for 2019 and 2020.
The property would only be 40 years if it's entered as an asset on the SCH C. So I'm wondering if something happened to import it to SCH C. Or maybe you do "in fact" have a SCH C business with Business Real Estate on it?
