As of ArcGIS Pro 3.4+, the Split tool has experienced an odd regression that prevents you from splitting line features on a vertex if the map projection differs from the feature Spatial Reference.
Splitting on edges still works fine, but if you want to split on a vertex it fails with a "Splitting Line Features failed." generic error. I'm not sure what exactly changed on the backend to cause this, but it's persisted through 2 minor versions and several patches now.
