Aha! Finally found it!

There are two, in this particular case, almost identical looking characters.

One of those is the desktop published form of \[Rule].

The other is the desktop published form of \[RightArrow].

In your MaxSteps->200 option that you give your NDSolve you are using the second, which means nothing to NDSolve, when you should have been using the first.

You don't realize it, it is impossible to tell, even with a magnifying glass, there is no warning message explaining what the REAL cause of the problem is, and you get what you get.

So you can stop attempting to desktop publish your arrows and just type a "-" followed by a ">", which Mathematica will then translate and desktop publish into \[Rule], or you can type Rule[MaxSteps,200].