DirectDraw with Bilinear Filter Not Working

[odditude]

I can't reproduce the issue on Windows 10 x64 with nVIDIA driver version 367.33.

GirlsGotRhythm16, can you verify that you've got the latest graphics drivers installed for your computer?

[OV2]

DirectDraw has been deprecated by Microsoft for a while now, I've simply left it in S9x in the state it has always been. It has no real way of enabling/disabling Bilinear filtering, so your driver might simply not do it. These were my findings last time I checked:
viewtopic.php?p=31577#p31577
Since it works for odditude I'd say it depends on the graphics driver.

[OV2]

I'd suggest to simply switch to Direct3D or OpenGL, those have no problems with enabling bilinear filtering.