finally i hooked up my MR816 to my win10 laptop (upgraded from win7,although in many ways it’s a downgrade as to user configuration especially,“personalize looks” as far as i can tell).
anyway i downloaded and installed the FW legacy driver,and reinstalled few time MR tools cuz i had problems with “yfwbus” not recognized,but somehow it managed to install 
but now all works and i don’t encounter the “sample rate” issues mentioned here. when i change projects with different sample rates Mr816 follows correctly !! or i am missing something ?