How to figure out why ReSharper is not rebuilding unit test project before running?

Recently I am having an annoying problem. When I go to Unit Test Sessions window and run some tests, ReSharper seems to completely ignore any changes in my code(even in the code of the test itself!) and does not rebuild anything. Because of that I have to rebuild everything manually. I think that problem is too generic to post on bug-tracker so I would like to find at least any additional information. For MsBuild I can always enable diagnostic logging and track all its decisions during build. How can I find what is the problem with ReSharper?

Versions: Visual Studio 2015 Pro Update 2; ReSharper Ultimate 2016.1.2.