QLocale::monthName() doesn't work correctly on Windows

Running the attached program on Windows 11 with LANG=fr_CA produces

"fr_CA" QLocale(French, Latin, Canada) "January"
"fr_CA" QLocale(French, Latin, Canada) "janvier" 

whereas on Linux the first line correctly says "janvier". I also tried it with WebAssembly and switched the language my browser is requesting to fr_CA and it produces the expected results like Linux. It occurs on both Qt 6.5 and 6.6.

It is unclear why the default constructed QLocale doesn't work on Windows, since it reports the exact same name as is used to construct the other QLocale.