Saving project in VS does not always update Unity

I’ve been using Unity with Visual Studio (& VS Tools for unity) for a month now and sometimes when I save my project in VS it does not update the game in Unity. When that bug occurs, it doesn’t matter how many time I save or modify my scripts from that point on, it just won’t be changing the game in Unity anymore.

To fix it I have to either reimport the script or I have to quit VS or Unity. Once I do that the changes I’ve made to my scripts that could not be saved and transferred to Unity that I’ve done are gone. So I have to rewrite that part of the code again.

This bug is quite annoying because I never know for sure if the changes I’ve made are actually saved or not and the only way that I can know for sure is by typing console prints or seeing that the changes I created are not implemented.

Is there a way for me to not have this problem occur anymore or is there a better way to deal with it?

Thanks for your help, guys!

PS: I’m suprised I haven’t seen anyone talk about this issue, am I the only one?

I’m using c#, Windows 10 and Unity 5.4.1f1, Visual Studio Professional 2015.

I have the same problem - solution:
You need to save ALL files in Visual Studio (the two diskette icon) for some reason saving a single file is not working.