The last few races Ferrari are the fastest car on mediums and Mclaren are the fastest on Hard tires.
The problem for Leclerc and Ferrari is as always Sainz. He is not fast enough and will also not let Leclerc pass.
Leclerc was clearly the fastest on the mediums and caught Sainz quickly but had to back down for temps and tires when he got in DRS.
So if they let Leclerc pass Sainz on the mediums, the gaps would have been big and Norris would stay at 3rd.
But thats why Sainz is leaving, good riddance.
Also don't know why Ferrari pitted both cars so early. They clearly like the mediums more and could go a few more laps.