If flights appear as if they were merged, there is a good chance that the T04 had been read from a folder where there are other T04.
Even if you import one single T04, POSPac will display all other T04 contained in the same folder as if they were merged trajectory.
One will appear purple, the other greyed out.
T04 processing needs to be done one T04 at the time.
To avoid that , isolate each T04 in individual folder and process them one by one.