Hello,   Sorry but VSM v4 does not work at all in a Linked mode environment as you discovered.  So you would either have to change the VCS configuration or not use VSM at this time.  Regards, 
I have on this forum seen that VSM 4 is not supported in linked mode however when I deploy 2 VSM one for each vcenter A and B in the web interface I am only able to manage the VSM which was installed last on B. No matter if I connect to the A vcenters web interface or B vcenters web interface I still can only manage theVSM that was installed last.
VSM In Linked Mode