A bug in version 1.15 of "Strange texture"

Hello! There was a small problem! The fact is that I went into a single world, turned on gamemode 1, put 2 blocks in the templates of the super-flat world, only turf and bedrock. Later, when the world booted up, I started building a house. Almost completed it, this happened. I think I broke some kind of block or something changed in the structure of the world. Textures are buggy and mixed up with each other. It was very strange. There was a place where strange textures did not load, there I broke a block of normal textures and all, strange textures appeared in another place where I broke the block. There are screenshots of all this. Game version 1.15. Nickname: Feonlade. Waiting for your help! Thanks.