Lingering tiles I can't erase, how do I get rid of them?

Hey, My first post here. I am quite new to the community of making games and at the moment I am working on a platformer I've wanted to do since I don't know when.

I'm having a hard time explaining this even in my own language, so please bare with me. Here we go.

So I have one scene atm, one tilemap and so on. I can "paint" tiles ok but there is some artifacts from a earlier stage that lingers. They have pink for the transparency and should not be in the scene at all. If I hide everything in my hierarchy the artifacts are still there. If I go in to 3D view they are still there, but I cant erase them, select them or hide them. They are not showing in the game view, but still they are messing with my OCD.

Any ideas? Ask if my explanation was not clear enough, please.

Images:

2D View

3D View