Bottom bracket square taper (cartridge) extraction, too tight in one side
I think you'll find that they are actually a different size.  I'm struggling to find any information about it online but I can show you a picture of a tool that should deal with it.  It's hard to say what the difference in size is but there is an obvious difference in thickness of the ends.  You probably just need to find the other size tool and take out the metal end first.