Skype for Business 2016 Client, keeps RTM version number

I use SfB, and in the about window it says: "Skype for Business 2017 MSO (16.0.4266.1001) 64-bit."

So it looks like it is missing alot of updates, but when apprying the newest update "16.0.4690.1000 from may 1.) it says that it is allready applied.

Is there a bug that keeps the version number from getting updated, or is my client not updated?