Yes, this is exactly the problem...it seems Nvidia control panel can only accept one profile for prepar3d.
When running more versions of p3d on one computer the profile, originally set for one p3d versipn, will be used by Nvidia control panel for all installed p3d versions on this computer.
The reason is, I guessed, is the naming of prepar3d.exe in all p3d versions the same. If the name of the applicatipns .exe file is the way searching for an installed application by Nvidea control panel, this will lead to issues....
I came to this conclusion as I read an other thread, A lot user now believe this can cause the crashes due to their graphics card in v5.....dxgi device hung errors...