"Fill" option won't stay when enabled

[Jekyll20]

While trying to set the textures on the faces of my bowgun model's "barrel" to fill, it never stays.

I turn on "fill" to make the textures look normal resolution, but after I save the project, export it into JSON, and add it to my resource pack, and run the game, it reverts back to the same, zoomed in texture every time.

Desired result: http://imgur.com/299NvJY

Actual result: http://imgur.com/eu2NA7p

[Major-gaming]

I've been having the same Problem!