multiple firefox and firefox portable at the same time

hello

I want to run Firefox desktop and firefox portable in the same time.
So, i just set the line "AllowMultipleInstances=true" in FirefoxPortable.ini (same directory as FirefoxPortable.exe).

however, when I start firefox portable, and I have an already running local firefox, I had two differents behavior depending on machine and operating system. For some machines, it runs correctely but for others, it does not work correctly and when you go to launch the second firefox Portable instance, it just spawns a new window from the already running instance(firefox dektop) and in the link we found the option "-no-remote" which prevents links from being opened.

I tried to add a batch with "set MOZ_NO_REMOTE = 1" so the problem to launch the firefox desktop and firefox portable is solved. But the persence of the option -no-remote in the link caused a problem to reload the page.

what is the reason for having two differents behavior depending on machine and operating system?
is there anything else I can try to get both my local firefox and the portable firefox running altogether?

thanks a lot !