Hey, fellow Canuck!
I think your trouble arises from trying to move only the poi when what you need to do (if I understand you correctly) is move your body along with your poi. Try this:
1-with poi moving in the manner you've described, turn 90 degrees to the right. (Keep poi spinning one in front of you, the other behind).
2-moving both poi at the same time, swing right hand up (front) and behind you on down swing AND swing left hand down (behind) and swing in front of you on the way up. Once the transition is done, keep spinning. [Most times we're so amazed that the move happened the we're like "wait, what was that", stop spinning and then we're all confused... Just keep spinning, you'll figure it out.]
3- turn your body another 90 degrees to the right to complete your 180 degrees turn.
If you are familiar with the wave, this is basically doing a half wave. Should you keep swing both poi back and forth after the first 90 degrees turn, it would be the wave.
Hint: to turn the opposite direction from starting position, it is the same principle but it would now be the low wave, so don't freak (like I did!!

) because in one half turn your hands are high and low in the other. It is absolutely normal.
HTH,
K.