OPC server with a Flexpendant and PC HMI App

DSRTM

I'm having odd FP freezing/laggy IO triggering issues on a duplicate manufacturing cell we're setting up.  this cell runs a FlexPendant hmi app, which is duplicated on a PC HMI running Indusoft webstudio and OPC 6.05

cell 1 (the working cell we're duplicating) operates at 90% cpu load (seems high, but it works).  Cell 2 with the "same" RAPID software (minor revisions including RW6.05.02) pins to 100% cpu load immediately.  If the PC hmi is shut down the FP app operates the cell nicely.  If the FP app is shut down, the pC hmi operates the cell nicely.  CPU load is 100% regardless of which HMI is up.

We've swapped PC's (the pn suffix is 1018), and have checked ethernet cables.  Note that we have not updated opc server to 6.05.02 yet, and that RW upgrade just occurred.

CPU load differences seems odd between cell 1 and 2.  cell 1 runs RW5.15 and the 1000 cpu.

does anyone have any suggestions about why the laggy response/high cpu load on comparatively "the same" systems?  The 2 apps seem to share resources, in that if we shut down one, the other responds ok.   We have a requirement for both systems, and have it proven functional on cell 1.....