The problem is not clearly explained. I don't know what to do with the "sum" parameter in Select, I'm missing the cut point in the Crossover method and I'm not sure what to do with some of the methods. I had to resign and check the solutions to clarify. The Crossover probability is not used at all. Actually, Crossover and Mutate are not symmetric, the first one don't receive the probability but the second one does. It's highly confusing the schema suggested, it could be more self-explaining, otherwise the explanation should be much better.

Instructions should say that the two separators (hyphen and underscore) may be used in the same case. Reading the instructions I didn't expect that and took me a while to figure out why my solution didn't pass the tests.

You made a point. Your solution is certainly wrong, or at least constrained to the characters that may work as "separators". But it passed the tests, so there's lot of test cases missing.

Too many conversions, too many things in the very same line, I wouldn't write production code like that...