out of tune ge10 EQ????

Hi…using cubase pro 9 on a Imac…using the equalizer ge10…no other plugin…i notice that when using midi instruments…example a guitar and using the tuner…it comes out of tune either plus or minus by 10…but if I only use the frequency eq…its in tune. Is there something wrong with the ge10 eq?..without any eq its in tune…wondering now if there are anymore plugins that will cause a midi instrument to go out of tune?..has anyone had this happen to them?