I suspect this is a language issue.
Please make sure that the PokerStars software is installed in English.
Does your table window have "Home Game" or "Freeroll" written in French instead of English, for example?
If that is the case then it won't match the hand history so the Hud won't find the table window.
Please enable logging (Configure > Options) and restart PT4.
Play one of these tables and attach the PokerTracker4.log file from C:\Users\yourname\AppData\Local\PokerTracker 4\ (which you can access from the PT4 File menu) to a
Support Ticket along with the hand history file for the session and a
screenshot of the table window so that we can see what is going on and see if it can be corrected.
Tutorial: Reporting a problem