Qt Creator sessions are mixed up

I do have a multiple sessions created in Qt Creator.
Each session contains 5-10 projects.
Loading time for the project list may take a few minutes to fully load.
While there is some projects still refreshing in current session if I switch to another session, sometimes I'm getting a combined project list of two sessions in the target one.
It happens not every time, but if it does it is really annoying.
To fix that I have to remove each project that not belongs to the session manually, or just force kill Qt Creator to prevent mixed session to be saved on the disk.