In admin > Modules > ckeditor > wbconfig > wb_ckconfig.js
Around line 187 it starts with:
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Commented out the <i> doesn't work. Your solution neither and my first aproach neither too.
refreshed mods, cleared browser cache and logged in again in the backend. Tried double quotes, single quotes and html space.
Like you said, it seems that looks like it's overruled by something.