Filters on the Windows platform should not be case sensitive. Apps that run on a particular operating system should follow the conventions of the underlying operating system. And case-insensativity for file system objects is an important convention on Windows. (I would certainly argue the same for case-sensitivity on Lunix.)
This was been discussed in the past (circa 2017), and a regex workaround was mentioned, but this really should be fixed permanently so filters work intuitively on their respective platforms without resorting to a confusing regex workaround.