Before, when I selected a component in PCBnew, in Eeschema the component was also shown (the views were synced). However, it does not seem to work anymore.
Is there some option to switch it on/off or is there a mismatch between the two applications? (I just created a new PCB, imported the netlist and updated it, and now I see all the components in one big blob). To place them logically, it is really ideal to see where in the Eeschema it is used.
Works from pcb new to eeschema for me with 5.1.2 under fedora. (Even for multi unit symbols.)
Make sure you select the footprint not one of its components. (Selecting the reference designator will not trigger the cross highlighting.)
I did some more checking, and found out it works as long as one instance of PCBnew/Eeschema is opened. But I split my project in two and opened two of each (PCBnew/Eeschema).