Nope, that wasn't it. It was strictly that my sell was 'too high' in their opinion. Same 'high' price last week went through just fine. So, the ECN has have changed something. And they haven't publicized it. My recent sell order went through. It's still high, but apparently is within their tolerance.
After this and their recent price increases, I am definitely looking for another broker.
Who has the best pricing currently??? assuming a decent-sized portfolio. I'm up for suggestions before I do my research. TIA.