The FIA took Sebastian Vettel under investigation, which did not slow down enough during the red flag.
Charles Leclerc spun in the session and returned from the gravel trap to the track. The Sauber driver brought the gravel underneath his car on the way back to the track, and the session was stopped with a red flag as there were too many gravels.
According to the statement, Sebastian Vettel did not slow down at that time and was under investigation.
This year, similar investigations were always given a grid penalty. If he's found guilty, he'il get a three-row grid penalty.