I'm unsure on the exact repro, but I can attach a save file which has the Issue present:
I was making some factory modules and just copy/pasting things around. Its possible there's some edge case on a single combinator which I then copy/pasted that empty blueprint many times. But now I've ended up with thousands of undeletable blueprints which effectively ruins your capability to copy/paste from that region and clutters the minimap


Save File with Issue present: https://drive.google.com/file/d/1vz1q4cYEXvtN19x8ztLnXyTbqEUZ8mXT/view?usp=sharing