It's been known for a while that the Perl date/time routines have a problem with setting Windows timestamps to dates in and before the 60s. Back in 2018 (https://exiftool.org/forum/index.php?topic=9192.msg47530#msg47530), I narrowed down the problem to dates before 1968:12:31 23:59:59.
Strangely, that time has been advancing ever since. Currently, any time before 1971:01:01 00:00:00 becomes inaccurate.
The earliest the date gets corrupted is still 1900:01:01 00:00:00. 1899:12:31 23:59:59 and earlier works fine.
Crazy.