Issues editing blocks or items

So what the problem is about is that. For an example. When i was editing, and trying to make my own Grass block texture. stuff goes wrong with the grass block side overlay. i tried and tried and i finaly got it look like it does on the editing screen. but on the layers. there is something alredy there called Atlas. that’s what makes the in-game texture changes. I wannt this to be fixed. This website says that it’s suppost to be easy to make a texture pack. But with this issue that u can’t even make a grass block without problems. it’s very hard. And i can not wipe away the colours that gets edited into the atlas grass_block_side_overlay. If there is gonna be an update for this. make the change at the editing screen like in the privous update.