This is indeed strange, because in my case it always works. I have a question now, because I see the UI looks a little bit different. What OS are you using the tool on ? And if you have some time to chat more, maybe you can write me on reddit or facebook to learn more about this issue
Viewing post in TileMaker DOT Map Editor comments
Yes, thanks for having a call on Discord with me to clarify those things!:D
The conclusion was that the problems happened because of the "tile size" set, they have to match the size of the tile used (by default the textures TikeMaker DOT comes with are 200x200 px, so "tile size" should be 200 until the users switch the textures with their own)
It was nice talking to you, and good luck with your game in RPG Maker!:D