Hi Valeri,
I tested with VB.Net and C# projects, both have the same behavior, sometimes it work and sometimes not, and the Sonarlint extension is enabled.
I've also tried to compile the projects, and also tried to create a solution file for the projects (because normally I open the project by double clicking the .vbproj or .csproj), and the result still the same: Sometimes work sometimes not.
And sometimes I will need to wait for a while then it works, but not all the time it will work.
I hope my explanation doesn't sound confusing.
Thanks.