The cause of this BugPattern is CloneAndModifyProgramming.

''What's the etymology of the bug?''

Briefly, you 'reuse' code by copy and paste several times (the 'tiles'), find a bug in the code, and fix it in most but not all of the copies (leaving one or more 'rogue tiles'). The symptoms: A bug that was supposedly fixed shows up again (and again) in different usages. The solution: Refactor out the common code, so that there's only one 'tile'.
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CategoryBug