Why do I see multiple waveforms on my oscilloscope in normal trigger mode?
Your signals aren't necessarily far enough apart for the scope to only show one at a time while running. 

When in "Run" mode you're potentially seeing the waveforms for multiple trigger events. But when you hit "stop" or "Single" you are only going to see one trigger event, which is why you only see one packet.

Normal trigger mode just means your oscilloscope won't automatically force a trigger after a specified timeout, I actually talk about this on our YouTube channel here: https://www.youtube.com/watch?v=AbjjF0vMPyo&amp;index=5&amp;list=PLzHyxysSubUkc5nurngzgkd2ZxJsHdJAb 

So, just because you're in normal mode doesn't mean you'll only see one trigger at a time, it means you'll only see valid triggers.