I only used Measure 1/Measure 2 to indicate that if I begin playback before the start of the clip there is no popping. Sorry for the confusion. I don't start projects on Measure 1, like everyone says the synths need time to initialize.
The popping occurs at any location in the project if I begin playback at the start of the MIDI clip. This whole thing seems tied to the start of the clip (and only on the first beat of the clip), whatever that might indicate.
@Promidi, thanks for your posts, I will go through that info and try to see what's what. I have the Behringer UMC202HD audio interface and I am using the Behringer ASIO drivers from their website, fully up to date. Everything else has been disabled/deleted, including ASIO4ALL. After all that, if someone tells me that the driver is still ASIO4ALL hidden in there I will laugh hard and yes, get another interface, so a definitive answer on that particular question would be nice. As near as I can tell it's ASIO. I explicitly deleted ASIO4ALL from my system based on other advice I've seen around the forum. But if I'm mistaken then, yes, I need to know that.