Something wrong for one of the examples for DateTimeFormatInfo.GetAllDateTimePatterns

URL: https://docs.microsoft.com/en-us/dotnet/api/system.globalization.datetimeformatinfo.getalldatetimepatterns?view=net-5.0

The second example on the page is supposed to show dates being unable to round trip. But when I was running the sample (both on try.dot.net and locally on a console app), the example is able to parse all of them.

So, the output looks like the following:
"Unable to round-trip 0 of 39 format strings."