Why unit setup shown 4 decimal, but sketch only shown 2?

Hi,

When I open a new part, then working on sketch, the dim. decimal only shown 2, but I checked unit setup, it shown 4 (see attached), I have to change to 3, some note shown the standard changed from ANSI to ANSI-MODIFIED (see attached), then I change to 4 decimal back, now the sketch shown 4 decimal. I really don't know why, Do I setup something wrong? Anybody get same situation? how to solve this problem?

Thanks

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SolidworksSketching