Thank you!! Such a random post to find the solution on. I'd been working on an advanced alert based on custom UDP all week. Kept seeing No Data on the UDP. Was driving me insane.
Called support this morning and turns out 80% of my db tables are 98% fragmented, and pollers have been hosing up all over. It's going to take days to normalize, but after adding indexing in SQL alone- I'm showing actual data values and alerts are triggering.
So, Bueller! Thanks for creating, replying to and essentially closing your own post.