Signature help is not shown until writing a comma in a string

[machitgarha]

When calling a function, the signature help should be shown. Unfortunately, putting parentheses and commas does not trigger it. However, strangely it becomes visible when you type a comma between parentheses (e.g. of a function call) and inside a string.

For example:

    throw new \Exception(",");

I reinstalled another version of Atom, and reinstalled the extension, but no chances. However, I'm not really sure whether it's a bug in this package, or the underlying language server.