I set an extreme example where 8th notes were played for 2 bars so that the difference was unmistakable.
It seems to me that what you did demonstrated correct behavior, in that it did play the 8th notes for two bars (as indicated by the P2 setting you made), but the chord for bars 3 and 4 is still C/E, so I would expect the bass note to still be an E, until you hit the C chord by itself, at which point there is no bass not qualifier.
Or am I missing something here.