Prior to a recent unknown date it was possible to Add > Construction Plane > to the Surface of an existing Body using an Offset value of 0 [zero] > then Sketch on the new plane and Extrude a new Body.
Attempting this today the desired Body was created but it becomes part of the existing Body used in this process.
If this outcome was desired it was [and still is] only necessary to Tap with a Finger on the existing Body Surface, then Sketch on the revealed Grid before modifying the Body.
A New separate Body was the intention of these actions.
Have changes been made or am I doing something wrong?