I am unfamiliar with Zen Controller so this may not apply, but I recall someone posting before that there is a glitch where the miner reports a theoretical hash rate instead of the actual hash rate. You may want to check the speed that is being reported poolside.
You were very right. I checked on Westhash and I was showing 0. Restarted the Pi and rechecked Westhash and low n behold, It was rising from 0.