Thanks for the info on differences between the physical and virtual fscsi interfaces. I do not have easy access to NPIV for personal testing, unfortunately.
Again, note the lsdev -P command for getting the default settings, and lsdev -R for the ranges of values for attributes.
Finally, you can use the odmchange command to set dyntrk to an unsupported (by IBM) value and see if that solves your problem.
If that seems to work, both you and the storage VAR could begin by requesting a design change. (Maybe, if you are lucky, the virtual driver does not check the value/ignores it. I suspect the virtual dyntrk is only affected by what happens at the VIOS level rather than at the F-port value (hope I got that right, I get SAN terminology wrong on occasion).
Michael