Corn_crop.json had age 0-7 upper block model reference the bottom crop textures.

proposed fix is any upper=true shold reference corn_top variant.

{ "variants": { "age=0,upper=false": { "model": "corn_delight:block/corn_crop_stage0" }, "age=1,upper=false": { "model": "corn_delight:block/corn_crop_stage1" }, "age=2,upper=false": { "model": "corn_delight:block/corn_crop_stage2" }, "age=3,upper=false": { "model": "corn_delight:block/corn_crop_stage3" }, "age=4,upper=false": { "model": "corn_delight:block/corn_crop_stage4" }, "age=5,upper=false": { "model": "corn_delight:block/corn_crop_stage5" }, "age=6,upper=false": { "model": "corn_delight:block/corn_crop_stage6" }, "age=7,upper=false": { "model": "corn_delight:block/corn_crop_stage7" }, "age=0,upper=true": { "model": "corn_delight:block/corn_top_stage0" }, "age=1,upper=true": { "model": "corn_delight:block/corn_top_stage1" }, "age=2,upper=true": { "model": "corn_delight:block/corn_top_stage2" }, "age=3,upper=true": { "model": "corn_delight:block/corn_top_stage3" }, "age=4,upper=true": { "model": "corn_delight:block/corn_top_stage4" }, "age=5,upper=true": { "model": "corn_delight:block/corn_top_stage5" }, "age=6,upper=true": { "model": "corn_delight:block/corn_top_stage6" }, "age=7,upper=true": { "model": "corn_delight:block/corn_top_stage7" } } }

Fixed in 1.1.8-1.20.1/1.21.1