I suspect what is going wrong is the line comment is being evaluated before the block comment and because they both share the some of the same characters that line comment is hiding the block comment.

I don't think that this is what is going on (at least not exactly).

If the line comment was ...

I'll first say that, with the as-supplied settings in Tools-Options-Keywords it has never worked right for me either in 3.97c or 3.97s. I won't go into details on that, but the options that work for me in 3.97c are:

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This has worked for me for ...