Set Child Actor Class w Splines and Actor Blueprint Class

When spawning actor blueprint classes on a Spline, with the Add Child Actor Component, and after setting them with Set Child Actor Class, UE puts out yellow error notifications that the Child Actors are not using a Static Mesh.

However, the Child Actors are spawned on a Spline, and the related Actor Class Structure also contains an option for Static Meshes. So it is unclear if this error is related to spawning on a Spline, or because the accessed structure also contains a SM entry, or if this is a bug.