Then I'm sorry, but nobody ever reported such a long pause. I'd say a maximum of 4-5 seconds is normal to load the whole scenery, perhaps even 10, but not more.
Are you sure you don't have *another* antivirus running ? Many users run with two antivirus at the same time, without realizing it, for example the Windows Defender + a 3rd party antivirus.
In this case, other than suggesting to stop using 2 antivirus, which is very bad for performances, if you still want to do that, you must exclude the FSX folder from scanning in all of them.