why are so many of my xray segments empty arrays?

We have a lot of different aws services creating xray segments, but I feel like might be related to the step functions, where we have xrayEnabled set to true in the cloud formation template. About 98% of the xray segments are empty like this: { "Id": "1-123xxxxxxxxxxxxxxxxxxxxxxxxxx", "Duration": null, "LimitExceeded": false, "Segments": [] } How can I work out what is creating these empty segments and prevent this? Thanks